Moneylenders are great and all, but they can sure get frustrating with all their constantly turning up and moping around after they've done a lot of work. Fortunately, there's some great solutions to this problem:
1) Ask the Bishop to take them off your hands. I don't even know how this makes sense, but the Bishop is pretty happy for your contribution.
2) Alternatively, just dump him in the Chapel and well, whatever happens, happens. You won't see that Moneylender again. Ever. Look, don't ask, okay?
3) Retraining him can be a good idea. He's got the skills needed that he can upgrade to a Rogue or a Mountebank, pretty easily.
4) Or if you prefer to work on his more honest characteristics, consider instead giving him a makeover and remake him into a Duke, or a Count.
5) Just be careful not to Develop him. We're not quite sure how it happened, but last time we told a Moneylender we were going to Develop him, we ended up burdened with a Loan and his Ill Gotten Gains.
6) Send him to work on the farm. You should get some gold out of it, or possibly more.
7) If all else fails, there's something you can do which... uh... well, Moneylenders have certain qualities that make them... uh, operate well in a certain condition which as ruler of the kingdom you can do but... uh... look, just send him to the Butcher, ask for a Feast, don't ask questions, okay? The Feast will even earn you some money. I suggest bringing a packed lunch.