Hey guys. I'm doing a swap from a d16 auto to a f23a1 5 speed. but got a few questions.

1) Ecu...since the car is obd2, for the time being because everything will be stock, can i just replace the d16 computer with the f23 computer to run it?
2) Axles....What do i use because of spline differences. I see post about some, but they all different lengths. Dosent seem to line up with the length of mine or with the intermedate shaft.
3)intermidate shaft.... do i need to use that? my current auto dosent have one. the drivers axle stretches to the trans. but the f23 has a shaft then the axle goes on end of it. both transmissions stop at same point. so dont understand why f23 has this shaft.
thanks guys