Is my neighbor "abusing" the kids?

It's a heartbreaking situation, for sure, but unfortunately, their family dynamic and how they choose to raise their children isn't anyone's concern but their own. If there where signs of neglect, substance, physical abuse, conditions that presented a health hazzard or one or both of the parents is engaged in illegal activity... then that's an entirely different matter.

About all you "could" do would be to speak to the manager about the excessive noise, but that certainly wouldn't help foster good neighbor relations. Asking to be moved to another available unit might be an option. Unfortunately, you can't always choose who lives next to you, but you always have the option not to stay.

I probably wouldn't recommend approaching them with your concerns directly. From the very brief paragraph you posted, and if she speaks that way to her children, she's likely to become hostile toward you... and from her perspective... my just be "one more" excuse to be unhappy in her life and take it out even more on her children.

About all you "can" do would be to extend a smile and a kind greeting to her when the opportunity presents itself. She may be feeling overwhelmed, alone and trapped in her life. Seeing a kind face can have a calming affect. Strike up a casual conversation at the mailbox. Knock on the door during a calm period and drop off a couple of coloring books and a box of crayons that your "ahem" neice/friends daughter/cousins brothers son "ahem" have outgrown. (Get my drift?) A small act of kindness that might help her feel not quite so alone in her little world.

No. They just have a different communicating style than you do.

You need to mind your own business, is what you need to do.

i would let cps investigate, they can decide for themselves if theyre being abused

No

probably