I think your gut feelings are the most important here. We can all advise you what to do, but ultimately, all final choices are yours. You know her. We don't.
So if you gut says fight, then fight we will!
First, money. If you can, keep helping her. You stop, that's just another avenue for him to take over.
Yes, buy a house near her. You reason is legitimate and makes complete sense AND the side benefit...you're close to her.
I think I know the answer to this, but what are the chances of you moving back into the house? My guess is no way jose.
Eventually this other guy will screw up. Let him and hope it is a big one.
Don't talk about him anymore. Unless there's a very good reason to, like the FB thing, he no longer exists. You are a thorn in his side, not the other way. Remember that and act accordingly. She will notice you never bring him up and that will make it that much more annoying when he talks about you.
So have you tried to ask her out to dinner or lunch, but on a day when you aren't working so there's no rush?
