YOU DO NOT NEED AN INTAKE FOR STAGE 2 OR STAGE 2+. The only thing required is a performance downpipe for stage 2, (stage 2+ is the downpipe and HPFP, everything else is a nice to have for more gains)
The stock intake will be fine. the carbonio ever so slightly better.
You will run slightly less peak power as a result if you keep your carbonio as they are about as much use as a chocolate fireguard. With an good air intake you could maybe add 10-15Hp to your stage 2.
Reference the HPFP, with REVO i would agree @ stage 2 sometimes its needed. Bluefin is much more conservative and doesnt request the fuel pressure as much as REVO.
FWIW my stage 1 was good, i found the stage 2 was really poor(very on/off with its delivery) with a huge drop in power of about 35hp at 5krpm. When i fitted stage 2+ it solved all the issues. (all ill say is dont expect to make huge figures with the bluefin, its not in the same league as the others, however it is a lot cheaper and more conserved, so better for longevity, so they are all reasons to stay i guess)
Any Qs mate, just ask. I had it @ stage 1, 2, 2+ and then swapped to another tuner where i went from stage 2+, 2, 1 then back to stock before selling. So i have a good base for comparison.