To clarify: The setting AGGRESSIVE RETALIATION is NOT turned on by default, that's right. I did it though and that's why I strongly suggest to make it OFF by default, because the game can get pretty much unbeatable that way.
Have to test the flamers, i have to admit i never used them... Must be bad experiences in the default game where incendiaries are pretty useless...
That Traitor guard still haunts me... That mission was like a nightmare, i downed everything left and right, even Sentinels and there he was, a single lone, tiny Chaos guard, killing my entire squad with his puny lasgun...
and later his twin showed up in another mission...
Oh, one thing: The defense corridor is rather expensive. In my game the 4 turrets could not kill a single raptor, 1.5 million credits for a (speed-bump) delay of 2 turns is a bit excessive.... Could also be RNG related of course, but maybe you could raise their rate-of-fire to make them more viable, haven't checked their stats, though...