I have a strainer in the tank to keep the twigs, leaves, big rust chunks, and anything I've accidentally dropped into the tank out of the motor. Then there is the big filter under the tank going to the pump. Do I need one in the engine bay as well?

i use 2...

1 before the pump (save the pump from debris)

1 before the carbs (they are expensive.....preventative measures)

i have an 8 micron at the tank and a 1 micron back at the motor. Probably overkill.

No, those are the regular fuel filters on your car, if you want an extra one for security it's up to you but it would be pretty much useless.

I'll probably put one in just for the hell of it. The PO had one on the return line back to the tank.