Can't help a lifetimes worth of keen observation, telling the truth and being stationed near many towns when in the USCG that have tried to throw out all the "vagrant" boaters...
We've got a number of dock rats whom to lesser degrees meet your description but to your point, they are friendly, know everyone and they watch out for your boat. A totally acceptable trade off.
What pisses me off are the guys who have boats in the marina(12-15 year wait list) that never take the boat out. I bet 30% of the boats have not left the slip in 2 years. That is disgusting. Put they pay their fees so the marina can't touch them.