5. Then take real parts of FFT result and output to data communication channel (because only real signal goes over the channal always, complex is just useful representation for processing).
You will get a number of subcarriers spaced by 1/T (from 1/T to (N-1)/T) with amplitudes and phases according to their input symbols.
For time T you should have M*(N-1) bits - this will define data rate and band.
For real application you also should provide a guard interval/cyclic prefix. And I'm not sure about syncronization.