I think we can distill this down into three seperate questions by now, which are best addressed and handled as seperate issues:
1, Is it acceptable to, as part of an IC intelligence release, include information that is specifically or most likely OOC information (i.e., the information refers to out-of-universe things, is written in an obviously OOC manner, etc)?
I think this is the easiest to address, so I'll hit it first: No. There's not reason to release information that you are certain or pretty certain is OOC information as part of an IC operation. By doing this, you are effectively dictating for another player or group of players how they play the game, which in my opinion displays a serious lack of respect for fellow players.
2, is it acceptable to infiltrate another corp and release information / assets / whatever as part of an IC operation, with all aspects of this being couched in IC terms?
I'm going to tentatively say yes on this. I'm not certain on it because inevitably someone will infiltrate with intent not to just kill a valuable ship or loot some assets but to crush an organization out of existance via a coordinated campaign of sowing distrust, embarrasment of members, etc, and while I'm not generally one for "space bushido" I like to think we have enough respect for each other to not be crushing our long-term projects just for the sake of crushing.
3, is it "cool" to use alts for an infiltration (note that this includes alts who do so under the IC reasoning of "I was payed" or "I do it for fun" as well as alts with a full backstory for reasoning)?
Well, here's the thing - generally, it's very very hard to turn a player from a corp they have worked in for some time. Barring storyline twists (which also happen to be rather rare) and particularly ruthless characters, you don't have a lot of options - doubly so because unless you want to include a "middleman" or "handler" alt, the person you are approaching is going to be met by someone who is obviously hostile towards the organization they're part of.
So, it may be more a case of "no other efficient way, so people are just going to use alts" than "cool/not cool".