do i need this
 

ok i have a edge ez tuner and the pump set at the 235hp setting. i am looking at 150 hp nozzles. i wont go any more than that and i was wondering if a 100 rapter would hold up?

yup it'll keep up with what you have going on

what is the highest psi i can run with still being safe. i want it to where at WOT, it will still be somewhere around 13 or 14.

I'm running 23psi and no damage or negative results. I wouldn't recommend over 25.

if it stays at 10psi or above it's fine