The main issue that I have with the scout-sniper mechanic is that if any of your agents hit an enemy, then all enemies "see" that agent. So your agent can be way off in the corner of the map, at night, covered in smoke, but if they hit an enemy, then the AI snipers can all light him up. This aspect both feels extremely unfair and is really confusing to the player.
I was watching Yeti's old X-Com Files streams, and he keeps thinking that enemies have ridiculous night vision and thermal vision because of getting fired upon in those kinds of situations.
I think larger maps can work in certain situations -- the cult of apocalypse missions can have tons of enemies. Bigger maps could mean that you don't immediately get jumped by tons of enemies. I think in general, a bit more separation between your landing site and the main force of enemies could be nice. Still have some enemies next to the landing, but opening the door and immediately seeing 10+ enemies is off-putting.
Larger maps in urban settings would be super annoying though, unless the primary objective isn't to kill all enemies.
Alot of the early game armour arent even to stop wounds, just to lessen the impact. Kevlar vest is prime example, its better than nothing and it changes that your soldier can survive 4-5 hits instead of 2-3.
But the armour after that, the armoured vest pushes the "lessen the impact" to "If RNG god smiles upon thee, you shall not take any damage", the shielded armoured vest pushes it to "Small arms will almost always do no damage" and then the tactical suit which goes "Most firearms wont even dent you". And the Tritanium versions pushes it to the max for a long time.
The Kevlar Vest definitely lets you soak pistol shots quite often, though RNG is a huge part of it.
Armored Vests and Tritanium Vests work really well, but you can still be one-shot because even if you are shot directly from the front, the game can still roll a side hit quite often (feels like a bit too often IMO), and those armors comparatively weak side armor. The biggest reason to use the Suits is that their side armors are quite strong too.