You made the right choice leaving the Crew I think. You want to turn you Xbox on for fun, not drama. Right? Over the years, I've left crews, groups, etc myself. It usually boils down to teammates complimenting me on my play style, only to get angry and throw insults when they face me due to team balancing, etc.
These days I'm simple. If someone invites me to a crew and I want to join, I give it a shot. The second I see some shit like what you've mentioned or what I said. I'm out. I tell the leader I've enjoyed my time with them, but it simply isn't for me. Most times it works out just fine, but there has been a few times where it got blown way out of proportion resulting in me hunting certain crews down and killing them for months. Good times in my opinion
If you annoy me in a game, I'll be sure to have a negative effect on your K/D Ratio. I like to hit people where it hurts
As for your Karaoke crush, I say go for it!