J.LAM

I am currently doing an H2B conversion on my EG hatch but i've been coming across some problems & i'm hoping you guys can help me out.

Situation 1: OVERHEATING : For some reason the car is overheating & I can't seem to trace the problem. I've replaced the entire radiator hoses, cap, etc.. I've replaced the water pump, changed out the coolant. But it still overheats. The first time it overheated the thermostat gauge didn't even show that it was overheating, but the second time around the gauge was working. The fluids are not mixing so i'm pretty sure the head is not cracked. Anyone have any suggestions to what the problem is?

Situation 2: VTEC not kicking in & Revs only till 5 RPM : As stated the car only revs until 5 and if you try to rev it higher it starts making a knocking/bogging noise? & the VTEC is not kicking in. Also the check engine is not going flashing on.. Anyone come across this problem? I'm thinking the wiring is off but I just wanted some feedback before I take it back to the shop.