Hey OP,
First, I am impressed you have kept a cool head with people just flaming you as a reply. Thanks for that. I read the whole thread just shaking my head...
Second, I can't help you with your question, but I to can say I get worked to death from some IAs. I am a GS, Sharpshooter, so no major defensive buffs. But I get one coming out of stealth, putting me in stun, get a second big hit, by then I am either stunned again or mezzed, I have trouble remembering, but by the 4th or 5th hit, im done. It makes me mad, I have 3/4 champ gear, rest centurion, but in the end, I don't get 2 shots off. I am trying to L2P against IA, but ****... i don't know what to do. I run around, and bam on my back again, 2 hits to death.
I love Alderaan so I can defend, and I have held my own until help comes for every class but IA.
GL to you in having someone help you or fill you in on play style. I'll be watching!