This does open up a few grey areas, which I'm sure will take time to work out.
As in, if a base is hostile to you, and when you jump in, if you are being fired at, can you then fire back? Problem is all you have to do is fire 1 shot and the base goes red and wep platforms then turn on. So this will involve a lot of record checking, if its even possible, to go back, find who fired first, or if that base was even truely hostile to the player to begin with (which would require checking the base admin's personal rep and matching it to the player in question).
Now of course, if this happened, you either get killed or escape. At that point, if you want to fire on the base, you must post first before doing so, even though it may have fired on you first.
Also in my case with the base I have inrp confrontations with, I really only need to hit it once with a CD to activate its shields, and make my point. And that's all I really worry about, I know in my Pelican I'm never going to destroy the base. But if i'm CD'ing it, is that an attack? Any weapons fire on a base is considered an attack? So a misfire of your weapons (especially by newbs) could be potentially damning.
I feel for 1 attack on a base, inforum RP is probably not needed, and if a player for the base is around, in game rp should suffice.
Only if you plan to repeatedly attack a base, or literally bring a fleet of caps on it should you really need forum rp. In my case I rp'd to cover my butt, but I havn't exactly been doing any significant damage.