So...
1. you can record the midi track by clicking on the red record enable button on the midi track.
2. You can send the synth output to an audio track, but you CANNOT record enable that audio track (you can just listen to it).
3. You cannot send bus outputs back to a track and record the bus output.
4. You can bounce to tracks in real time while playing your synth but you can't tweak synth properties while you do this.
5. You can send your audio output to an out on your interface and loop it back into the interface Inputs and then record the inputs (watch out for feedback loops when doing this).