Don't think you're missing anything except you don't mention some decent speakers - I'd use what you have right now. the beauty of using BIAB 'as is' is that you can alter the tempo, loop the song, change the feel etc. to keep the gig going well.
We've looped the intro of a song on gigs when our singer sin't quite 'ready' and other times we haven't - can't do that if you've made your backing tracks into a cd, or put them on an i player etc.
Also, not that your public would notice, but I like the fact that each time I generate a tune, the real tracks are slightly different from the time before, which adds interest for us musicians!
Finally, if you found a cracking bassist for a gig, simply mute that instrument and they can 'step in' - next time, if it's just you, un-mute it and off you go!!