To simplify the matter of chatter on beaches, the instant an unknown pirate begins a lengthy litany, I hit ignore. I do not think it fair for participants to spend precious time dealing with verbose pirates.
With regards to friending observers, organizers, crew, et al, this presents a difficult process for long time pirates. I prefer not to delete a friend who is coming back when the Kracken hits POTC.
The boot feature for privateer ships may be an easier solution for unwanted guests.
One solution for contestants who leave early may be to have observer ships hit the sea if a contestant leaves. This would prevent svs openings for any pirate to join. In order to keep observer ships from becoming targets, they could quickly sail outside the tournament area.