We've chartered in the Caribbean for over a dozen years and are amazed at some of the folks they'll allow out on a charter. Your 8 years on a Pearson 26, including a 200 mile trip indicate a degree of experience with sailing and navigation. I'm not sure I'd lend you my boat, but I'll bet you'd qualify for a charter in a benign area like the BVI. We've met a number of other charters in the Virgin Islands who have never owned a boat and had less experience than you.
Our first charter experience in the Caribbean was an eye-opener. My wife and I had just returned our boat and were sharing a taxi to the airport with a foursome who had also just finished their charter. We were sharing stories about where we went and what we liked the most. When we told them about taking a slip in Spanish Town, BVI, where we were impressed with the slip fee of less than a dollar a foot, their reaction was, "You docked the boat yourselves?"
I don't mean to disparage your interest in sailing schools at all, but you needn't sell yourself short, either. You might check with charter operations like the Moorings or Sunsail to see what they think about your qualifications. Sometimes they will put a paid skipper on your boat for the first day or two, if they think your qualifications are marginal. Otherwise you can do the crewed charter for a lot more money.
All that said, you should follow your instincts about taking courses to become a better sailor. I wish there were more sailors out there like you.