I love this board, too...... so many ideas and suggestions. The problem is that there are so many to choose from.
It sounds like you've decided what you would like to do but I'll add my 2 cents worth. I'd add a border. And I'd pick whatever color I wanted to bring out in the houses. If you have this in a pink room, I'd choose pink. If you want the green to 'pop', I'd pick green. The blue background color would disappear if you chose that.
The binding could look like a frame if you pick a different color but a very skinny frame. I think I'd use the same fabric that I'd pick for the border. Then it's just one larger frame. Plus, it doesn't have to be super perfect width wise.
It's really a cute quilt. You did a fantastic job.