Returning player in need of help...

[REDace0]

Yes, that does help, but it also raises three additional questions:
...
3. I think I read on the forums somewhere that you have to be lvl 25 to join a Grand Company. Is that still the case or should I be looking now?
...

You have to be 25 to join as a full member, yes, but you can start doing the earlier quests as a provisional recruit at 18 or 22, I forget. Just visit any Grand Company headquarters in a city's market wards to see if they'll offer you a quest yet. You have to do 3 major quests for each company to be eligible to join one. You can take on the fourth quest for all 3, but you are only required to do it for one. After it's complete, there will be a fifth trivial quest for your induction.