As I understand it, traffic isn't a huge issue; rather, it's the prevailing winds. Sailing from the Texas Gulf Coast to the Western Carib can be done, but you'll have wind and waves on the nose the whole way. Doesn't sound fast or fun. I think most people head east up the ICW or close offshore to Florida and then sail from there. During the sailing season (pre-Hurricane season, of course), you should have steady S/SE winds and good sailing right up the coast. If you sail offshore, you will need to keep a constant watch for unlit oil platforms and obstacles. From Florida, you can take short hops down the Eastern Carib or tackle the longer passages to Western ports.
Get a copy of Jimmy Cornell's Cruising Passages and study the wind patterns some. Keep us posted.
Hey Tetra - are you really upside down? Actually this is good info. We're starting to plan some coastal sailing for next summer - probably out of Galveston. Thanks.