OP - In a spot like this with a loudmouth at the table, I always keep "one player to a hand please" at the ready. If someone said, "I know what I would do" I'd say that. It usually works. If it doesn't, the dealer should then be aware of your request and hopefully will back you up.
Since I don't like talking during a hand, I usually won't say anything else unless the guy has really gotten to me, in which case I'll usually regret saying something. But you know, you have to stand up for yourself. And saying OPTAH almost always works.
As for leaving, you're well within your rights. I agree with everyone saying that a better player wouldn't have to leave because these people wouldn't get under your skin, but I'd also leave because it would get under my skin too. I'd love to find a way so that annoying people don't annoy me. Headphones work pretty well but they're not infallible, and sometimes the antics of big-mouth players just tilts me like it's 2004.*
Nope. This place is seniority only, and there are far too many people in line ahead of me. It'd take a decade for me to even get full-time poker shifts, and I'm pretty sure the room will close long before then. That's why my last shift is tonight.
No wonder they're such ****-ups. Good luck in whatever new gig you get lined up.