Thanks for your feedback, everyone. I'm trying to improve my attitude and I've decided to say no to things that come up, instead of just doing them. I think that should help.
I really would like to move Izzy to somewhere more ideal, but right now, it's not a smart financial decision, since none of my jobs are all that stable. That said, I'm considering taking a lesson at the place I want to board at, just to see how I mesh with the other boarders and owner and all that. That way I wouldn't just be blindly jumping into something that I might not like.
Good news! I got a call from the local tack store and I am now the proud owner of the saddle I had on trial. Of course, it matches absolutely nothing else I own, but eventers aren't supposed to care -that- much. We'll make do for now.