Turns out research credit you get from interrogations is really powerful as well, in many cases halving research times. IF you know what you're doing you could get your desired tech faster by asking the right alien how to build it.
I'm getting intrigued by the cover mechanics. So, you take an alien's aim (say 90), modify it by cover (say hunkered down in half cover = 20 x 2) and the result, 50, is the odds to hit. So half cover isn't worth it, but full cover hunkered down (40 x 2 = 80) would mean only a 10% chance to hit. Dense smoke grenades will give you a bonus 40 (normal 20), and so can be used instead of hunkering down for your forward troops (and is actually a better solution for troops forced into half cover). Skeleton armour gives a +10 defense as well, trading HP for evasion. And finally, if you go for the combat druggie smoke grenade, all defensive bonuses are lost.
Finally, give a rookie a light plasma rifle (+10 aim) and a SCOPE (+10 aim) and bang: instant boss.
LB, you really are a massive geek.