I'm a shitty ETF2L mid scout, so take my opinions with a grain of salt but here's a couple of ideas I had
Reduce explosive jumping damage (soldier and demo)
+soldiers and demomen have more mobility
+More diversity in shotgun/gunboats choices
+Indirect Scout nerf due to more shotgun soldiers and more soldier mobiility
-If buffed too much gunboats might not be worth running anymore. This would be counterproductive with my intention of having an overall more diverse choice in unlocks
Crossbow changes
Reduce all healing from crossbow by x% AND/OR Remove passive reload
With the current power of the crossbow and the absence of any other unlocks in the meta a change clearly needs to happen though I oppose the ban of the crossbow. A rebalance from Valve's side needs to happen. I personally prefer a small nerf to the amount healed and bringing back the old mechanic of an active reload.
Even if this nerf'd happen the crossbow would still be meta. So buffs to the needleguns would still be needed for crossbow to not be the go to pick
Scout
I think the simplest nerf to scout would be reducing the knockback from the scattergun. A change that would buff soldier bombs and nerfs the pocket scout meta TF2 has moved towards over time. Obviously I'm not for reducing knockback to a point where denying soldier bombs is no longer possibly, though I feel it currently requires too little effort to do succesfully