2. doesen matter u can change drive in both, 2.5" disc of course.
imo as long as it isnt all fresh from sony to the store it shouldent be any problem, i doubt the reseller updates the fw and it has only been out for like 3days approx.
think i read somewhere that it won't work on "newer" models, something about chip change or similar, the infectus that is.
1. original jb allowed to use backupmananger, and when they released psgroove they removed that function to use backup mananger as they dont support "piracy". but the psgroove was edited shortly after it was released by some other hacker to enable backupmananger use again, dunno about all the ports but i guess they used the "fixed" psgroove code to enable it.