Loose the boom vang... No need for it..
Batten's being under tension did more to stretch the sail than I would think damage that line.. If the line is is good shape it wouldn't be the first thing I would change..
I wouldn't bother with a painter or anchor.. There isn't a good place to stow an anchor, and I don't use a dock so I don't have a need for a painter.. Pulling an old boat up on the beach is pretty easy to do from the Dolphin striker..
For a swim.. Once you are certain your mast is sealed and the boat doesn't take on lots of water what I do when the winds are light and I want to swim is simply capsize the boat.. This leaves a hull in the air which makes for a nice dive platform.
If the winds are up you won't have a need to swim
... and in those situations don't let go of the boat.. It will drift away fast...