Returned player: which job is more accepted?

There is a limit quest every 5 levels still, including one at lv75- but they're all extremely simple until lv95.

Since you're returning, your merit mode is left at whatever it was set at. The xp/merit mode can be changed at any time from any place, but you can only spend merits in your mog house. In your case, to order to level up, you must switch to xp mode and complete the lv75 limit quest.

Since leveling is done in alliances, your contribution is less significant, so your job matters very little. You'll probably come across several naked lv50 players in an alliance while you are leveling at lv75+.