I do most of my cruises on Arcadia and Aurora and find my balcony cabins on them more spacious (and with much more storage, including drawers!) than on Iona (which I won't be trying again). Had problems with rowdy kids (and some adults!) when I was on her too.
Good reviews from some of you on Elizabeth House. So am using for my Arcadia 24 nighter in September. £268 including parking. Not bad and cheaper than my usual, Holiday Inn. Hope it is ok.
Are we allowed to recommend insurers? Have found one whose premiums are really good if you have more serious conditions. Don't know if they are bona fide though!
For beaches
Bus to Grand Anse, Grenada
Taxi to Spice Club, Bonaire
Share minibus to Carambola Beach Club, St Kitts ( or day trip to Nevis)
Taxi to Boatyard (expensive and crowded) or Harbour Lights (cheaper and quieter) in Barbados
More to Caribbean than great beaches though, especially if new to the area.
Enjoy your trip.