Jibs,
I'll let someone else speak to your chances on the east coast, but Cabarete right now in my opinion is fairly saturated with small restaurants, including at least one bakery in the center of town that has been there for years, as well as a few decent sandwich shops. Finding space in the center of town where you'd have the most traffic isn't that easy now either.
Since you've never been to DR, I'd suggest you plan a few months just visiting/living/learning - even working for an existing bakery for US$1.50 an hour- before you commit to investing in a business and growing costly roots. There are many things you might not be taking into account including getting residency so you yourself are working legally, higher cost of equipment in DR, need for a generator to run you equipment at 5 a.m. when the lights are out, sourcing potable water for your cooking, locating your source of flour and other ingredients (you might not find the same items you are used to and need to modify your recipes), how to incorporate/file taxes/etc, language challenge with Dominicans you hire, how employee benefits work, and so many other things.
If you can't afford or don't think it makes sense to spend several months (or longer) just learning the environment before you make the move & start a business - then I'd suggest it's a really bad idea!
DR's a great place to be if you have money.
DR's a great place to be if you don't have money, but have set aside enough for your flight home when times get too rough.
DR's
not a great place to be if you are on a shoestring budget and are investing much of your savings on a business that could very well fail.
If you've got sufficient funds... forget the bakery and enjoy the sun!