To start i have a 90 CRX stock d16ZC with a master power super60(supposedly), Dsm 450, walbro 255, log mani on 8 psi tuned on crome

like everyone else on here i want more power! so i Gave someone a call today about a Zex dry nitrous kit... if you can answer the following questions thanks in advance im new to nos

1.What is the largest shot i should possibly attempt?
2.What is a the throttle position Device i have read about that only allows nitrous only when WOT
3.Do you guys just tap in the intake for injection or is there something i can buy that allows me to bolt on and screw nitrous Feed line in?
4.When tuning with nitrous+turbo how much timing should be taken off on average?
5.Should i just stay turbo and no nitrous?