You don't need to "check the 121 box" at a regional in order to get hired at a major, especially since you have previous air carrier experience via AMF.

Might help, might not, but I think you'd be a fool to leave a job making that salary for flying/managing a CJ in order to drive a RJ, just in the *hope* it'll help get you to the next level.

There's tens of thousands of other pilots trying to get hired at major airlines right now - you're just one in the pile, so you'll have to wait your turn. Much like the 91 world, NETWORKING can help elevate you in the pile, and can be anything from LORs from existing pilots at the airline you want to work for to attending job fairs attended by your targeted airlines.