I can answer your bridge question. Yes, Isabelle won't let you place a bridge there as long as there's a house there. It's the exact same amount of space that Bruce had between his house and a bridge in my town. I had to let him go to get a new one put in, and now I have to get rid of Marina to put a 3rd one in. Man, I wish the building space requirements weren't so arbitrary. Isabelle, this bridge can fit if we try hard enough!