You can't help people, who don't want to be helped. Nor can you fix things for people even if they want you to. They have to fix things for themselves, but you can support them. For example, I have relatives who paid off their son's debts with money they could I'll afford to lose. Their son created yet more debt. Had they supported him paying off his debts gradually, so he felt the pain, he would have learnt a useful lesson sooner rather than later and avoid straining his relationship with his parents.
As to dealing with difficult neighbours, do your homework. Decide what outcome you want. It is easy to react to your feelings, rush off and confront people, but you rarely get the outcome you want. I've been prevented by my DH from rushing out and confronting people. In his previous life, as a police officer, he dealt with many situations between neighbours that have escalated. I know how I feel when people go off at me, even if they have reason to. They do not achieve my cooperation. But when I am told I am appreciated, but there is a problem which could easily be resolved, I have no problem in responding positively. Sometimes it is best to do nothing at all and see how important what has happened is to you later when you feel calm.
For getting old, moving may be the only option, but not a quick or easy solution. Are there any neighbours you would like to get to know better? It may help ease things if there are friends close by.
