I figured it out so I'll answer my own question. It works just as I had hoped. Adding Aux tracks, which can be assigned to your interface's inputs and then showing the console (F3) where you add effects etc. is what I was looking for. It helped to open the show template "Real Instruments".
For small gigs taking only speakers, laptop, interface, keyboard(s), other instruments, mics, and cables. The interface is the limiting factor for # of inputs and outputs.
I like it.