The only place I like better than St Thomas is St Martin. So far I would say I like the eastern Caribbean better than the western.
Belize is building a port but currently still uses tenders, and unless it has changed, you tender in from a long way out. Unless you are really interested an up close experience with life in a 3rd world country you should stick to a tour. Belize City is not primitive but is very representative of a capital city in a poorer developing nation. Not a place to wander around alone. Belize is very conscientious about preserving their natural and historical resources even to the detriment of financial gain so there are many beautiful locations that include natural jungles and beaches.
Ocho Rios has a nice cruise ship pier and well developed shopping near the port. The Dunns River Falls is a top tourist location but pretty will fills the day if you take a tour that climbs the falls. We took a private tour with a short stop at the falls then went on to see the rest of the city and surrounding area. It is true that the sales people can be insistent, even in the shopping malls, but the pressure was only uncomfortable in the flea market area at the terminal. Up the road from the pier the shopping village was great and the shops and restaurants near there were great. There is a small cramped beach near the ship but I would recommend checking out tours to one of the beaches away from town.
I have not visited Isla Roatan so I can’t help there.
A similar itinerary stops at Costa Maya. It’s primitive but we had a great time at the nearby beach. Lots of packages are offered at the cruise port but it’s best if you can just get a taxi to take you there and choose the “package deals” once there so you can see what you get. The women in our group loved the open air massages under canopies on the beach.
2012 Carnival Destiny
2011 Carnival Splendor
2011 Carnival Pride
2010 Carnival Legend (w/ Hurricane Paula)
2010 Carnival Imagination
2009 Carnival Valor
2008 Carnival Freedom
2008 Carnival Facination
2007 Carnival Triumph
2006 Carnival Miracle
2005 Carnival Victory
2002 Carnival Imagination