Pretty much what Rad- said. Right after Raithwall is one of the best segment of the game, as you gain access to a lot of different places and challenges. You can tackle on very hard bosses way before you realistically should, explore areas you aren't exactly ready to face but the game doesn't stop you (heck, it is quite rewarding to go to these places), and on top of that you can do all of this with a very nice ally by your side if you take the time to recruit him and stop moving along the story to keep him with you a little longer.
In fewer words: that part of the game is fun and provides some nice challenges. Enjoy it.
On a side note: keeping a save right after Raithwall is the best thing to do, as it allows you to enjoy said part of the game and try different second jobs. Itwould have been better to be able to change all jobs at this part for people who wish to do so, but hey, I'm not complaining.
If you are motivated, it is possible to just start the game from scratch, not select any job and complete Raithwall (despite having no bonuses and access to good equipment, it believe it to be definitely doable with decent levels and good use of items, although some bosses may become quite hard as a result; it is a good thing the Mythril Saber you get along with Basch can be equipped by anyone, since it is a unique weapon which doesn't need any license to be used). This way, once you kill Belias, you will be able to unlock every jobs and try all the combinations you want. You just need to keep a separate save file for your experiments.
I really should try that actually.