I think if you have the capacity, calling a lot in pugs on medic can be really useful and can actually be good practise. I find that when I call more on med in pugs, I feel like I'm actually impacting the game.
Also I think you should only play pugs as med if you actually enjoy it. I found that playing med pugs burned me out because you have to deal with some real rodents sometimes. I may be repeating something someone else has said but picking up another class is suuuper useful, and understanding the limits of the other classes will certainly help you with awareness in game.
To play medic you need to be able to balance priorities unlike other classes so the best way to do this is to get to a point with your game knowledge where things don't really surprise you. For example you know that at X hp you probably need to use uber if a soldier is on you..
I say all this stuff not based on anything I've seen from you btw, I've never had any issues with you in pugs !