Thanks for the responses guys!
It seems the general consensus is that it will still retain the effect if I swap gear mid-shot.
It would also be problematic to macro due to rapidshot messing up any time based macros.
Fortunately for me this isn't an issue at all, as Rapid Shot is virtually non-existent for CORs. Both RNG and COR get the JA, but it's blatantly obvious that either COR gets a much, much less proc rate by default or the proc rate decreases with weapon delay. Either way, I'm fairly sure that in 2+ years of playing Corsair, I could count on 2 hands how many times Rapid Shot has proc'ed for me, and I was probably /RNG at those times.
Unfortunately, if you Rapid Shot, I'm not sure if the power/sTP gear would get counted, which could lead to some awkward TP levels.
I believe you are indeed correct. When any 'instant' ability kicks in, it's truly instant and leaves no time for mid-cast modifiers.
As to blinking - I'm sorry, but <stal>'s introduction feels like years ago. I would go as far as to openly ridicule anyone who complains. You know, if the initial enlightened discussion fails. /em polishes his gun...
It feels like years ago because it was
years ago. I'm 90 WHM and RDM, and I couldn't agree with you more. It absolutely blows my mind how many healers complain about people blinking. If I'm spending hours to maximize my macros to do the most efficient damage possible, and to maximize my effectiveness for the party, the damn healer can take the one-time, 20 second investment to change their macros to <stal>.
Thanks for the help guys! I'll give it a try!