SS,
First of all, your neighbor sounds like -- dare I say it? -- a nutcase. Boundary problems all over the place. In the first instance, I think she has problems letting go of her son. I don't think it had anything at all to do with you. Would probably need more info to confirm this, but you might want to consider that.
In the second instance -- well, that is just nuts. She obviously has issues of some kind. From both instances, it almost sounds like she has some problem with impulse control or something -- like she has no internal "editor". ?????
Re: the BB -- this is definitely not how it's supposed to work. This guy is not good BB material. He is causing more harm than good. I would document every little thing, then go back to the organization. If you don't get any satisfaction from them, escalate it. You're supposed to make a big commitment when you sign on as a BB/BS, to commit yourself to the child and to be responsible. This is nonsense.
...maybe it has something to do with "younger generations" (ugh! I hate to say that). They are much more flexible in their perception of time and other things than we (I) are. Also, many of them have been brought up with a rather strong focus on their needs. It might have something to do with that. But no matter -- it's not good for your son, so try talking to the guy and help him understand, and if that doesn't work, go to the org.
I have a friend who was a big sister to a girl who had a bad family background, and my friend was just wonderful to her. The mother was the nutty one who put her daughter into all sorts of predicaments and sabotaged her outings with my friend; but my friend is very responsible and strong and generous, and I recall vividly how she committed herself to that girl. That's the way it's supposed to be.
My thoughts.