Think about what you do in your town:
Place water
Handle Contract for new town owners
Handle Grief Reports
Ereps?

You have to think about who would be able to do as many of these things, im not saying that because then you dont have to do nothing.
But you can ask them to hop onto something if you are busy.

I would look for someone who is really active in your towna dn give them a trial of helping members out and doing things before promoting him to a Owner in your region.
You could also make him a owner in one of your towns and see how he gets on with promoting and maintaining that town.
You can still help of corse but too many people throw there new owners right int he deep end rather then letting em learn how to do things and what you do :p

I hope you find someone!

 

A co-mayor will be able to do everything you're able to do. You can always demote them though. Or impose limits on them/kick them out if they break those rules.
It's not as bad as it sounds. The town will always be yours, and there's no way a co-mayor can take that away from you. Any damage they can/could do is fixable. But I'm being overly negative, most co-mayors are extremely helpful, and they don't break rules for no reason.

You can of course give people trials like Mission suggested. But if you can't find anyone in the town that looks promising, I'd personally write up a fairly long template for people to fill out here on the forums. If you ask the right questions, you can find people that would be dedicated to your town.