There's not a lot of shore dives on Roatan and the best of those are at the AI resorts - Coocoview, Reef House etc. Which don't have a great beach - or really any beach at all. The best beach is in West Bay but there's no shore diving there except one shallow site. Some of the boats - esp. from the West End - do return to the dock between dives so some of those are short trips. They all try to do 2 dives between around 9AM-Noon then afternoon dives.
The only longer rides from that area are when you run to sites like the Aguila or Spooky Channel - or the drift dives off the west end of West Bay. Or if they go around the island to dive Mary's Place but you can also drive over to Barefoot Divers for that - it's 5mins. off their dock. Barefoot Cay has a pretty nice beach also - they treat it for sand flies. Which is the other big problem on most Roatan beaches - even with Deet we were bit up pretty good by the end of the week.
Betweeen Curacao and Bonaire Curacao has the better beaches
by far. There's a lot of them and many are also shore dive sites. You can see a lot of them here.
Scuba Shore Diving Region: ABC Islands
The only really decent beaches on Bonaire are at Plaza Resort or Harbour Village - maybe Eden Beach if your wife doesn't want to go too far into the water. Pink Beach is about the only public beach I know of on Bonaire that's also a dive site and calling it a beach is IMO a stretch since there's ironshore at the waterline.
Another advantage Curacao has is that many of the beaches have improvements, i.e. shade, a snack shop, a beach operator etc. Many also have a dive operator on site for tanks etc. You do pay a small usage fee at some of them to use the facilities - waived if you rent tanks usually. Dive sites are farther apart on Curacao so you'll be driving a little more between them. On Bonaire once you leave the resort areas there are no sites with any facilities at all. Both have basically the same dives as they're on the same reef just 50 miles apart. Dives on Curacao were a little more diverse IMO - a lot of Bonaire's south side starts looking pretty similar after a few days.
Another more expensive option for both is Grand Cayman. There's at least a dozen shore dives - many with a dive operator on them and Seven Mile Beach is a nice stretch of sand. However there's no shore diving off SMB - the reef is too far out. And if you stay in that area, you will have to drive a short distance north or south to any of the shore dive sites - several are clustered on the North wall and others are in/south of Georgetown.