So the first complaint is that there are loud, drunken, rowdy people on the dock. As one who is typically part of this group, I say lighten up. If you want solitude, go to a mooring. I would much rather be on a social dock than one where everyone is adversarial to each other. Boating is supposed to be fun, so don't get so uptight when people have fun. I spent most of this weekend in a 12 boat raft up with both power boats and sail boats. We roamed from boat to boat drinking and having fun. We went over to one of the power boats with a generator to watch the Bruins kill the short birds. It was great! And we very typically do something similar every Friday and Saturday night. There is a group of about 15-20 boats with people from their early 20s to 50s that treat their boats like summer homes and spend the weekend on them. A lot of them only leave the dock a few times per year but they enjoy their boat every weekend. But they are a very social group and are always there to catch your lines as you come in.
Second, it sounds like these guys are at least being responsible in that they are drinking at the dock and not while driving their boats around. Also, your story about the 4th doesn't make sense to be upset about. They drank and had a good time until midnight and then tried to quiet everyone down. I don't want to tell you what time our dock party broke up last 4th. And the marina across the river from us has a Pirate Party annually that typically ends around dawn.
Third, I still don't get the issue with the chairs on the dock. We have a very long dock (about 1/8th of a mile). The first 2/3rds of the dock is about 8 feet wide and people routinely have chairs out on the dock. You can still walk past and wheel a cart. On the remaining 1/3rd of the dock its only 4 feet wide so no one puts chairs on that portion. We are on the very end (2 slips in from the T head) and have to walk past all of this. There is never a problem passing and we usually get stopped talking to friends several times on our walk up the dock.
Lastly, when you were walking up the dock, did you say hi? Did you introduce yourself? We live on our boat (well, just the summers for now until we get our house sold) and whenever we see a strange face on the dock we take notice of what they are doing and what boat they visit. I will often go up to them and introduce myself and find out what's going on. The other people on the dock like that we do that because it helps with security. We have stopped a number of situations that include teenagers partying on their parent’s boats without permission, stopping thieves, etc. If you were a strange face on our dock, you would have got strange looks, possibly a "stranger danger" from my Bride and I would very likely have walked up to you and introduced myself.
Sorry to sound so harsh but I just think you are the one really out of line here. Relax and enjoy yourself. Maybe some of the issues that are causing you to sell the boat have you in a negative place right now and you need to just calm down.
Good luck and fair winds,
Jesse