Regarding the head, best way to avoid issues is to open it once you are under way as far from land as possible (consider the current as well) and then close it prior to heading into an anchorage.

We typically open it, let it drain (just give it a minute or so) and then close it, so its never left open.

CanadianSailor is right on about it not being a cruise - that is important. There's no one to clean up except those on board!

And expectations are also important - We had one couple come with us one time and the husband had been before, but his wife hadn't. Her expectations were a little different from reality. I think she expected to sleep with the hatches open and hear the waves..etc, but it was October with periodic showers and it was hot so we ran the A/C at night. So setting expectations is always important. She did have a fun time, it was only marred by the sea lice that gave her an awful rash making it very uncomfortable for her - they spent their last couple of nights at Scrub Island and went home a day early because of it.