Pretty exactly much what I expected. I think QoS is your best bet, too.
There's two ways to set it up quick and dirty, just to see if it works:
1. Prioritise all UDP traffic (games are almost always UDP, bandwidth heavy stuff like youtube is TCP):

• Source Adress: Any
  
• Destination Adress: Any
  
• Protocol: UDP
  
• Operation: QoS
  
• QoS Operation: Set Priority

2. Prioritise all traffic from your PC:

• Source Adress: [Your Adress]
  
• Destination Adress: Any
  
• Protocol: Any
  
• Operation: QoS
  
• QoS Operation: Set Priority

Considering that you're using ethernet I doubt it's the wifi itself. If you get high ping "especially when someone opens youtube" it sound more like a network load problem.
Have done a speedtest before and after the line went down?
Have you tried loading a youtube video on your pc or another pc connected via ethernet while playing? If the same happens it's definitely a network load issue.

It's not that large, but it's acceptable. Not a lot of space for cable management behind the motherboard tray, but there is some which can't be taken for granted at that price. Dust filters aswell, though no modular drive bays.
With only one HDD I'd just stuff the cables in the empy drive bays and be done with it. With a modular PSU there shouldn't be a lot of them and it's the easiest and fastest method for this case.
The PSU is on top so I wouldn't use SLI/XFire for airflow reasons and you'd need a Z mobo for that anyway.

Can't wait to see if there's non-K and possibly non-Z overclocking and what results the usual suspects achieve with it.

Performance & Cooling.

So definitely wait a bit.

Even if the new CPUs end up too expensive in Australia it's doable.

CPU: Xeon E3-1230 v3 instead of i7-4790, -0.3GHz, -iGPU, -110$, fair trade I'd say.
Cooler: No overclocking so just drop it.
Mobo: No overclocking, no need for Z97. -100$.
RAM: Not much I can do if he actually needs 16GB. Colour scheme though.
SSD: Minor savings, slightly newer.
HDD: Just an alternative, get whatever is cheaper.
GPU: 270/270X is a bit faster. Before I saw your edit I was about the suggest the GTX 960 as a step up, but with the 270 it ends up at 1354$ so it's not happening.
Case: µATX ftw. -150$ if you drop down to something really basic.
PSU: You've got a 750W PSU for a <300W build? That's money well spent. Or did you go SLI? Anyway, Antec HCG-520M, decent semi-modular Seasonic. If you insist on 80 Plus Gold there's the G-550.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E3-1230 V3 3.3GHz Quad-Core Processor ($335.00 @ CPL Online)
Motherboard: ASRock H97M PRO4 Micro ATX LGA1150 Motherboard ($109.00 @ CPL Online)
Memory: Kingston HyperX Fury Blue 16GB (2 x 8GB) DDR3-1600 Memory ($135.00 @ Umart)
Storage: Samsung 850 EVO-Series 120GB 2.5" Solid State Drive ($99.00 @ IJK)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($69.00 @ Umart)
Video Card: Gigabyte Radeon R9 270 2GB WINDFORCE Video Card ($175.00 @ IJK)
Case: Silverstone PS08B (Black) MicroATX Mid Tower Case ($44.00 @ Umart)
Power Supply: Antec High Current Gamer 520W 80+ Bronze Certified Semi-Modular ATX Power Supply ($104.00 @ IJK)
Operating System: Microsoft Windows 7 Home Premium SP1 OEM (64-bit) ($129.00 @ Mwave Australia)
Monitor: LG 22MP55HQ-P 60Hz 22.0" Monitor ($155.00 @ CPL Online)
Total: $1354.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-08-27 19:49 AEST+1000

But the most important thing:
WAIT ANOTHER WEEEK

1. Well I can't really answer a question before I understand what you actually want.
2. Ok, but don't be dissapointed.
3. Good.
4. I didn't ask for that, you provided the correct model numbers for both CPUs, unlike many others.
5. Just had to make sure.
6. Laptop model numbers are more useful, this only tells me it's an ASUS laptop.
7. We'll see.
8. There is no Laptop Build Thread because you can't build a laptop. I know every pc build question outside of this thread gets at least three replies linking this thread, but for laptops a new thread would've been fine.
9. You could've been a little more patient. No one here is paid to answer as fast as possible, so a couple of days until you get a response are normal. Also new laptop CPUs will be released this September.
10. No, I was just having fun. You'd have noticed a burning sensation if I was roasting you.

Ladies and Gentlemen hold on to your seats and prepare to be amazed by what a monster of a post I can get out of two lines.

First of all are you talking about laptops? If you want performance avoid mobile CPUs/GPUs. If they are laptops stop and think if you really need one. If they are weird all-in-ones or even weirder pre-builts forget about them immediately.
Either way I don't see a lot of PC Building happening and this is the PC Build Thread, I'm kind of obligated to recommend you to build a pc instead.
If you didn't want to get recommended to build a pc you probably shouldn't have posted in this thread.
All of this is based on the assumption that with "regular GPU" you mean the i7's integrated GPU and not a dedicated GPU (in that case I'd want to see that abomination).

But don't worry, I'm just getting started.
If we're talking about "games like cs" which games are we talking about exactly? CS, CS:S or CS:GO? Various non-Source games similar to CS or Source Games including various versions of CS? Or Source Games but not CS itself?

But wait, there's more!
Both the i5-5200U and the i7-5500U are dual cores with Hyperthreading. The i7 got a higher clock rate and turbo boost plus 4MB instead of 3MB cache.
But then there's the graphics. While the 940M is ~60% faster than the HD 5500 it's still squarely within shit tier. ~60% the performance of a 750 Ti, equal to a 250X at best is still not good. Don't worry, if you're "lucky" you'l never be limited by the GPU anway, since the heat produced by the 940M might get the i5 to throttle down into oblivion anyway. All things being equal the i5 is more likely to throttle but the i7 got even worse graphics, either way performance won't be good. However things aren't equal. It depends on the exact laptop model's cooling, but more likely than not you won't get the full performance for more than a few minutes.
Now think about the fps you'll get with a 1GHz dual core. Not much. Do you still want a laptop?

Last thing, it's not really important but did you mean:
1. "Both SSD's [word missing] are 8 GB"
2. "Both SSHD's caches are 8 GB"
3. "Both SSDs are 8 GB" or
4. "Both laptops got 8 GB of RAM"

"accidentally"
RAM: Kits are cheaper if you still want to go with 16GB, otherwise get an 8GB kit.
Mobo: We've been over this. Z87-A. Look at that price. Look at it. Now tell me why you don't want to save money.
SSD: The 8[b]5[/b]0 Evo [b]250[/b]GB is cheaper and faster than the 840 Evo 120GB. Is that such a hard concept to grasp? There's also a combo deal with the Z87-A, you could get the 850 Evo 500GB for 45$ more than the 250GB version.

8GB RAM, 250GB SSD:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($327.99 @ SuperBiiz)
Motherboard: Asus Z87-A (NFC Express Edition) ATX LGA1150 Motherboard ($59.00 @ Newegg)
Memory: Crucial Ballistix Sport 8GB (2 x 4GB) DDR3-1600 Memory ($39.49 @ Newegg)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($89.99 @ Amazon)
Video Card: EVGA GeForce GTX 980 Ti 6GB Superclocked+ ACX 2.0+ Video Card ($674.99 @ NCIX US)
Case: Fractal Design Define R5 w/Window (Black) ATX Mid Tower Case ($115.99 @ SuperBiiz)
Power Supply: SeaSonic G 550W 80+ Gold Certified Semi-Modular ATX Power Supply ($78.99 @ SuperBiiz)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($16.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 OEM (64-bit) ($86.75 @ OutletPC)
Total: $1490.18
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-08-25 05:06 EDT-0400

16GB RAM, 500GB SSD:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($327.99 @ SuperBiiz)
Motherboard: Asus Z87-A (NFC Express Edition) ATX LGA1150 Motherboard ($59.00 @ Newegg)
Memory: Crucial Ballistix Sport 16GB (2 x 8GB) DDR3-1600 Memory ($77.99 @ Adorama)
Storage: Samsung 850 EVO-Series 500GB 2.5" Solid State Drive ($179.99 @ Newegg)
Video Card: EVGA GeForce GTX 980 Ti 6GB Superclocked+ ACX 2.0+ Video Card ($674.99 @ NCIX US)
Case: Fractal Design Define R5 w/Window (Black) ATX Mid Tower Case ($115.99 @ SuperBiiz)
Power Supply: SeaSonic G 550W 80+ Gold Certified Semi-Modular ATX Power Supply ($78.99 @ SuperBiiz)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($16.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 OEM (64-bit) ($86.75 @ OutletPC)
Total: $1573.68
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-08-25 05:07 EDT-0400

About the GPU: The Gigabyte G1 Gaming or Asus Strix are better, EVGAs support is probably the best though.

Did you update/change anything?
Did you check the fan profile?

I'm not sure what the exact threshold is but after the completed boot it's not supposed to turn until the GPU reaches the threshold temperature (either 60, 65 or 70°C depending on bios and model iirc).

EDIT: fucking 1 second ninja
EDIT2: So just to make sure I got all of this right:
The fans worked fine up until today?
Even while ingame with the GPU at 85°C the fans won't spin up and you've checked that either visually or with a program?

Ok, then I'll just give you some general advice:
Don't make a part list in advance, you never know what'll be on sale.
Don't build around the GPU for TF2/CS:GO. It's almost irrelevant for Source games, you'll need a GPU but that's about it.
Don't buy the 212 Evo if it's not on sale (and it never is in Europe). There's plenty of coolers that perform the same or better at a similar or even lower price. It's just hard to beat when it's discounted from 35$ to 25$, which happens fairly often in the US, but basically nowhere else. For 25£ ~ 40$ it doesn't come close to being worth buying.
Don't buy an aftermarket cooler at all if you're not overclocking. The stock cooler is good enough.
Don't buy a random PSU. First calculate the wattage you actually need (in your case <300W), then check reviews. The CX750 is oversized and bottom tier. Far better 300W PSUs can be had for less.

Just post here again one or two weeks before you'll actually build it and I'll make a part list for you.

Well it is a complete part list (no SSD though), but before I tell you why I wouldn't get these parts, could you tell me why you chose these parts?

It's most likely what you're looking at with your budget.
Two things though:
1. There's a lot of different i5s, so working out which one exactly to get has to wait until you're doing the exact part list and with that I'd wait because
2.

I don't think there is any current CPU that gets you less than 60fps in TF2 so this should be easy.