by ignistello on reddit:
It seems after you have finished your company quest(~level 20), you can instant level 15 by talking to these NPCs as the correct class.
Swaenhylt in Camp Drybone(Eastern Thanalan) for Thaumaturge
Wihtred in Hyrstmill(North Shroud) for Conjurer
Aniud in Hawthorne Hut(East Shroud) above the town for Lancer
Chechezan in Horizon Camp(Western Thanalan) for Gladiator
Zacheus in Little Solace (East Shroud) for Archer
Urswyrst in Moraby Drydocks(Lower Noscea) outside gate near Chocobo Porter for Marauder
Adelard at the South Hammer(Western Thanalan)(20,27) for Pugilist
Also once your level 26 and completed the Toto-Rak dungeon, you can level your character again to level 29 by talking to the guy outside your grand company station.
I've done my company quest and talking to Swaenhylt did absolutely nothing. I'm currently at Level 23.
I have to say, I'm impressed on how it handles freezes. So... I used the Duty Finder (which is quite slow by the way) and managed to get into a Tam-Tara duty. It was a pretty standard party (archer, tanks, healer) and we were almost to the boss. There are several enemies on the screen (which I was hitting from a distance) and the two fighters were doing their thing. Suddenly, it just completly freezes (frozen screen, PS button unresponsive, music still going, you know the usual freeze) and I had to turn off my PS3 (three beeps of course). Fortionly, I didn't have to go through that dreaded hour long restore scren and was able to start up the game within a minute or two. I log-in... thinking that I was going to lose everything I did in the dungeon and that the party would have been disconnected. The not up-to-date character model it showed before getting back in worried me, but I was presently surprised. I get back in to find all the enemies gone, the party further up ahead, my character exactly where I left him, and even a chest for me to plunder. The party was very forgiving (espially leaving the chest for me) and the chat logs (which appearently kept going) showed them discussing how I simply went AFK for a couple minutes. So... there are you have it. When FF XIV freezes, it simply treats it as going AFK. You do NOT lose anything and it will only be a minor inconvenience in whatever you are currently doing.
It is also worth noting that getting signed out of the PlayStation Network (an error that usually requires restarting your PS3) has absolutely no effect on the game. You can just cancel it with (o) and contenue doing whatever you were doing.