The RF match-up is a straight TU-to-TU comparison. If a RF firemode costs X TU, the unit will RF against a target after they spend X+1 TU in visible range of the unit. This is why low TU firemodes are better for RF -- the target gets to spend less TUs before receiving reaction fire.
Hmm, which is problematic. Often the enemy isn't in line of fire very long, favoring running round corners right up to you and firing repeatedly. To be able to actually damage him it needs to be both high damage AND short TU operation, which is rare. Wave damage on lasers (pistol especially) would likely fire then, but not be enough damage to actually stop anyone. Though with multiple guys all there to hit... maybe. I'll try using a combination of shotguns and laser pistols next time.
On a related subject, since long ago on a different game I gave up trying to use smoke grenades effectively and somehow never tried it in this one... I was in error! I just tried using them and definitely like them. Helps a lot in using mobile cover. Still aliens seem to plow into the smoke and open up at point blank range, but usually they don't seem to have much TU left to do much, for whatever reason. Odd since even without smoke they tend to walk straight up to you before firing *shrugs*
Out of interest H-Hour, do you happen to know if the computer DOES allow the aliens to know your precise position continually or is there some 'sense' of where humans are if not in view? Does it just remember last position and what seems to be their attacks are just coincidence? It seems a little much. I've had aliens wait and wait, but just as I move in range (despite being out of sight) they wizz round the corner and blast me.