Question about the vvti and engine limiter in Spec V

[SpecV Rulez]

Well, this specv reaches its power peak at 6000 RPM. It cuts at 6500 RPM.
Would it be better to take the engine limiter of to make it go faster or
not, or is it possible to take it off?
Question number two is vvti kicks in at 5000 RPM angine cuts at 6500RPM so i
shift at 6200 RPM, which gives me about 1200 RPM of power band. Now what i
wanna now is would using a vvti controller to drop it to 4000 RPM work? Is
the thing which kikcs in at 5000 RPM is the variable short air intake
instead of the vvti which runs contuniosly they say? If it is the new and
shorter and cooler air intake, is there a way to drop the rpm of that things
start?
They say this car gets its 10 more horspower than the SE-R is because of its
modified air intake and specially tuned exhaust. So if i get a different
exhaust and a new cold air intake would I only increase like 2 horspower
because i am taking something out which already increses the horspower like
10 and put another thing in which gives 12 horsepower.
Well i am confused as hell i hope i didint  confuse you guys too. I used to
drive a throttle body 350 camaro before so i need to do was changing the air
intake manifold and get a better muffler cause i already had 2.5 inch
exhaust pipes. But this high tech car confuses me about what to do. Help
please.