Hi Dioxine! Great thing you still keep developing (I lost number of times I've already said this), and there few things about balance I wanted to mention (yeah, it's already been mentioned before by someone else):
1. Totaly op melee - only disadvantage is get hit from "overwatch" enemy what actual only for mercs (in case you got your troops more or less experienced) and even this easy avoided by smoke and using numerous obstacles (~100 TU more than enough to kill 1-2 mercs with hammer while jumping-out from tree 50 feets away from them), and with advanced melee make thins even easier.
2. Useless ak-47, tompsons, etc compared by damage guns. Actually, if you wanna play only firearms in begining - your only solution is give boarding cannon and hancannon to best marksmans while using others ppl as scouts and molotov-throwers. Not much fun, boring, repetative.
Yeah, I know you resolved this problems by adding flamethrowers, special ammo (still enjoying all this variety of acid/conclussive/etc damage types), but there still a problem for me to play firearms squad at first part of the game. And I hope there be more enemies vulnerable only to one type of damage, so, for example, acid weapons not only temporary solution to increase firepower until you increase it with lasers and so on, but only way to deal with type of enemy. In short it'll be cool if someone like boomsaur will have 95% resistant to all bullets types, 75-85% to explosion and only 5% to acid. It'll make research of captures/killed enemies more vital for survival and make this "magnifying glass" you speaking about totaly suitable for gameplay. Yeah, I see the problem "how should I pass this terror mission full of boomsaurs and my lonely pistol-rifle squad" but it can be solved by calculating when new types of enemies will appear and when average player get tech to resist them.