2" exhaust is fine for the power output you`ll probably be making,loop over the inlet pipe over the top of the supercharger towards the drivers side headlight area,injectors too small for any boost at all mine ran out of duty cycle as soon as it was flat on n/a let alone came on boost,throttle bodies pretty small on them for sure so an upgrade wouldnt hurt on mine i built a new inlet manifold because i didnt like the 4k-e design and thought it was pretty restrictive.
Throttle body has to go in front of the charger or you had better have a solenoid cut as soon as you get off the throttle or you`ll stall the blower/engine because it will try and boost against the throttle plate and boost will go ballistic very quickly,blow off valves sound absolutely horrible on them so don't go there.
Ecu get a link,don't muck around trying to use a standard ecu you`re wasting your time or get a different aftermarket ecu.