I hope you keep us updated. I am curious how it turns out. IMO, you are hosed. If they are in their 's 50's, they have no clue what you are going through with a little one. And from your post, they do sound inconsiderate.
I am going through something similar. In our cul-de-sac there are about 13 kids and they play on our property, especially in our backyard, under our bedroom window. They wake up my 2 yeard old from his nap, it takes me forever to put him back down. We have spoken to all the parents and they simply do not care. The kids run wild and my only recourse is police involvement. But honestly, I dont want my house burned down. So we are moving. Did I mention these are elementary kids?
Bad neighbors suck and they dont change, IMO!
We were thinking apt after this, but after all these stories, I am thinking townhouse with a garage only!