There are many different water treatment products available, but ultimately what your tank is made of will determine what you can use. One rule: Do not use any product with chlorine if you have aluminum tanks.
Only issue with Dockwa was getting a slip we didn’t really fit in at a marina that really couldn’t handle a boat our size. All ended well, but if we go back to Falmouth we’ll deal directly with the larger marina that isn’t in the Dockwa system.
Absolutely! Many small (+/- 32’) sailboats on the market right now. Many under 10k. Power market for same size is a little tighter as many see boating as a way to get away, but don’t know how to sail. ;)
Also an elementary teacher. I’ve been spending summers on my trawler to prepare for life aboard when I retire. It is the best!! I can not wait to finally retire! ;)