Except for when you stack -12 and the line trooper can't shoot back, you have an equal chance of critting vs any form of camo/ODD as you do a high...
Are you asking about whether or not Martial Arts can be used when declaring Engage? Is that the question?
When you're directly contradicting the FAQ they issued, I don't think you can claim any certainty about their intent.
You're trying to make it OK to draw Line of Fire through scenery. That isn't how the rules read before the FAQ to begin with.
I'm assuming that you're talking about, let's say, a 1 Wound Hacker taking 1 Wound from Brain Blast, while simultaneously suffering the effects of...
Facing is absolutely part and parcel of whether Line of Fire exists. It was before, and it is now.