I'm just adding here that the trick yoiu mention for recording virtual tracks live using the gate and the side chain sounds very interesting. I'm going to write this down and try it also.
This sounds like something that might apply to what I'm trying to do.
The Noise Gate trick is the only way I know to record a virtual instrument played live as an audio track. You don't really use the Noise Gate as an effect, just it's Side Chain Monitoring capability. It's a bit complicated at first, but it works great. However, as Martin said, I don't think you need to do that in your situation. In a typical situation, you would record the Virtual Instruments as MIDI data. That way, it's much easier to edit the data. I hope it helps!