Artist? you mean performer?

Anyway, you've said you're keeping Ringabel as whatever that is, so. If you're not looking for damage output from him, then I would recommend thief, because you can actually get some really nice items from stealing. Basically just steal from every major enemy until it says they're not carrying anything and you'll find yourself rolling in goodies. Thief is also a useful class simply for boosting slow characters speed up (which can be very handy for a healer) This can be done either by actually equipping the thief job, or by using the speed up support abilities it unlocks.

Also, Mug is a good alternative to steal because although it costs MP, it's essentially an attack and steal in one go, which means you're not wasting valuable attack rounds trying to steal and potentially failing. You can also combine godspeed strike with speed boosting daggers and mimic (rank 14 freelancer ability) for some heavy damage.

That said, monk does have some nice moves later on such as pressure point (ignores P.Def) and Qigong wave (ignores defaulting) which can dish out heaps of damage even when other characters are struggling to make the cut.

As for time mage, you're not far off. It is largely hailed as a useless class, besides certain abilities it has which are useful for specific game-breaking strategies, namely hasten world and slow world. If you're not worried about them, then just ditch it.

Since you mentioned not using Tiz's white magic, I assume by default that you are fond of having some black magic on hand. Now, personally I wasn't a huge fan of black magic, mostly because I found it either unnecessary or unsustainable, but you can always make him a black mage and give him some of the fantastic support skills from the red mage class.

A lot of the jobs I might recommend come from later on in the story, so for the sake of spoilers I won't just rhyme them off, but you can see the full list here if you want to peek ahead: http://finalfantasy.wikia.com/wiki/List_of_Bravely_Default_Jobs

Otherwise I might recommend:

For Agnes, :

If you really want Ringabel to become a powerhouse physical damage guy, then is a viable choice, but be aware that it comes at a cost, as you'll be losing a lot of HP by using that class' specials.")

Ultimately it's up to you. Your build is pretty different from mine, but hopefully I've given you some things to think about.