So, skimming through the thread I may have missed a point or three.
Long and short of it is: IC infiltration is very viable, and has been done on several occasions (including current situations). The character acts as they need to when interacting with their 'marked' corpmates. As your OOC choices (whether to shoot at a particular target, whether your logistics happen to hit the person that needs them when they should, etc...) are the exact same as your IC choices are, I don't see a problem on that end.
As for "OOC Comms" (forums, intel channels, voice comms, etc...) I see them as IC lite; No, they may not be intended to be IC communications, but if your CEO says "hey, we're going to be pulling an op at this time on this date." you can assume that your character (IC) would be privy to this information (IC it would read the exact same most likely).
That all said, maintaining a reasonable communications channel between the infiltrator and the person getting the information is the difficult part IC. Using alts is "easy" if the person has very few qualms with it, and there's the guarantee that the infiltrating character won't defect. However, it's much easier for an information broker to pay off someone else to do the grunt work (or pay someone already on the inside to defect), rather than try to run multiple infiltrating characters at the same time. Risk in that case is being played, the character/player being paid to be on the inside is feeding false information while taking your kredits. It's one of the reasons I like the intrigue of the intelligence/infiltration side of the game.