Total firetruckin bullshit!

In most circumstances, if I saw a new neighbor that needed a 'talkin' to'...I would talk to them in a nice, friendly way, to tell them what kind of neighborhood I live in, and how I would expect them to act might be a good idea to have another neighbor along to agree)

In your case though, I think with that kind of talk, all you would get would be a blank stare. They've probably never been in the kind of neighborhood environment that you are talking about, so what you would be saying to them would be like from another planet.

I see 2 main issues you do need to address though.

1) The dog. That dog is a danger to all the children (and most of the adults) in the neighborhood. I would warn the owner that the next time you see it out in the front yard off a leash, you will be calling Animal Control, and getting your gun out.

2) The 'gatherings', trash and language. They need to be taught what is acceptable behavior. I'd keep this talk on the 'nice' scale, just a casual mention to whichever adult seems to be the most reasonable. Nicely inform them that when you see trash laying around, you will have to assume it's coming from them, and will end up back on their property - so it would be nice if they just picked it up and disposed of it properly in the beginning. Language - kids around, not a good example, etc......

If you don't nip this in the bud, they're going to end up the ones 'in charge'.