Playing over tracks is not a bad idea, and is more visually interesting to the audience, assuming you're playing full two handed parts. Having to follow the strict form of a track does not appeal to me though, but you could probably learn to use "midi markers" if that's an issue for you?

For smaller speakers, there's lot's choices out there. My battery powered Bose S1 Pro, along with a very small Fishlight power station, has been enough to power up my KB, vocal effects and mixer for the outdoor patio jobs I got for the summer season.

Best of luck to you with your new direction. I admire those that like to reinvent themselves.