Well, first of all, my condolences. It's no fun when there are band conflicts -- especially those that blindside us.
For the past 30 years I've followed these rules:
1) I only play in equal-partnership bands that are ruled by committee. If there's a bandleader who calls the shots and I'm not really a full-fledged member, then I have to be on retainer as a hired gun like any other straight job.
2) Unless I'm touring with Seal, James Taylor (a la Jimmy J.) or a comparably badass and professionally established singer, then I only play in instrumental bands. How many bands have we otherwise played in where the singer was actually the worst musician in the group but at the same time the frontperson or focus of the audience? Isn't a band only as good as its weakest link? The last time I played in a vocal band the lead singer asked why I prefer instrumentals. I told him the vocals are too often unintelligible, unintelligent and get in the way of the music. The look on his face was priceless. Of course, my mouth was smiling. But my eyes were not....
3) The smaller the band, the better. I prefer trios. More room to stretch and with each successive addition to the group, the potential for conflicts and BS goes up logarithmically (LOL). To say nothing of the expanded band footprint, stage volume, etc.
Of course, my instrumental trio, Sizemo, only gigs once every 9 1/2 months, so what do I know?