I had 6 weeks of annual leave saved up. Im changing to a job that pays significantly more than my current salary. When my boss asked me what it would take to stay, I asked for a salary increase of 35% which he begrudingly gave me. Then I quit. This equated to an entitlement payout of about $10,700 instead of $8000 on my previous rate, an extra $2700. And the new job still pays more than the increased rate I asked for.
Not if you’re at-will. In that case, you can be fired and you can quit for any reason.