GA is any thing other than airline flying.
I have only done a bit of airline flying and that was regional airline stuff. (Smaller airports as well as capital city stuff).
This is what I did in Australia.
Instructing, bush flying - which encompassed charter and scenic flying, aerial work (Coastwatch) and bizjets is all
GA. (
General aviation).
Not quite sure where I would put "night freight" but instead of flying people I was flying parcels. Generally quieter and a lot less trouble.
In short, I don't do "airline flying" as I find it too much of a routine. I fly a bizjet now.
*If* you have your pension/superannuation etc all sorted out then that's one BIG headache removed. Take your time to read "G-SXTY's" posts about his journey. He did make it to a Dash 8 but the cost was his marriage.
A good friend decided that the cost was not worth it and stopped flight training.
Ag flying is not for the feint hearted, you'll probably need tail wheel time and a host of other requirements.
MCC = Multi Crew Co-ordination.
ATPL = you'll need that to sit in the LHS of any thing bigger than 5700 kg. Otherwise the CPL + IR etc is fine. You'll find that if you do the ATPL subjects, that covers the CPL and IR subjects. If you do the 2 separately, there's more exams. Yep, that's JAA/EASA for you...
At the moment, you don't have a CPL so there's no job available.
A low houred CPL holder will struggle to find any work, most add an Instructor rating on or pay for a rating or wait until hiring is more prolific.
There are jobs out there, you just need to network and be flexible where you live.
Good luck.