I'm going to keep this brief as possible.
I'm on the LXJT side flying the -145, but I would imagine, if you wanted the CRJ most likely they would give that to you-just my opinion. Not sure about being based in ATL, not sure how junior it is on that side.
As for my side, doesn't matter if you put "Will fly" or not, usually you will be used on reserve regardless due to low staffing. This time last year I flew 15 hours/month on reserve..this year I'm flying right around 75..if I wanted to fly more I'm sure they would find something for me. Usually for a given month I can count on one or two days not being used if I'm lucky.
As for gross pay, if you are being paid 23/hr that roughly equates to $23,000/yr.
One great thing about XJT is the contract. We usually stay in decent hotels, 11-12 days off a month on reserve which isn't too bad compared to other places, fair sick policy, commuter clause, and airport reserve is only 4 hours-unlike other places. That being said...do your research. Nobody knows what's going to happen to us in another year or two, but then again the industry is changing so quickly, no matter where you go things may look very different in a few years. Good luck.