Cozumel currently has two piers up and running, so unless you are the fifth ship to arrive, you will be docking.
Again, you should be able to dock at Roatan. I have only been there twice so I don't know if anything has changed. The cruise ship terminal is in the Coxen Hole area and it is very easy to get around. There are very poor areas of the island so don't stray off on your own too much. You can negotiate a better price with the cabbies if you are persistent. I usually just pay their asking price to help bolster the local economy just a little bit. Try West End Beach... beautiful!!
Belize.... tender (last year, it was about a 15 minute ride to shore)