Your route plan sounds a bit ambitious to me, given the amount of time you will have. But the basic route you describe, S and E to the eastern island chain, is done many times each year. The best overall guide for this run is Bruce VanSant''s _Passages South_ and, if you stick with your plan, I would encourage you to buy it right now as it will help you anticipate many aspects of your run.
Basically, you have until June to get far enough S and W to avoid a possible hurricane''s path...and of coure, there have been early storms in late May some years. The two reasons you would go so far east before turning SSW for the ABC''s is to lay a fair course and to see the island nations along the way...which requires some time both to make the miles & to smell the roses. And you may need to factor in some weather delays, as you''ll be (motor)sailing against prevailing E & SE winds, seas and wind-driven current. Depending on when in April you leave and how much shore time you want to spend, I wonder if you''ll have the time to do all 3 things: go SE to the BVI''s, sightsee along the way, and subsequently get SSW sufficiently to be assured of no storm complications by let''s say 6/1.
The weather in April and May should be wonderful. The Trades lighten up, the cold fronts stop penetrating the Exumas or further south by then (or are quite weak if they do...) and you should find the anchorages relatively less populated until the Virgins. This period will also make sailing across the wind from the N islands (PR
, VIs) down to Bonaire a bit more feasible, altho'' that''s a very optimistic route given the W''ly current and perhaps a S''ly component in the E''ly Trades. I''m sure that''s why you''re thinking about leaving from the VI''s, as you''ll find it easier to lay Bonaire and enjoy going downwind to the other islands.
I think you need to make a fundamental choice: stay with your route and end up in the E Caribbean as the storm season arrives, or stay with your destination of the ABC''s, expect a bit less time enroute, and/or change your route a bit. You might want to consider provisioning (the ABC''s are relatively expensive) in Santiago, inland of Luperon, DR, and then sailing via the Mono to head out for whichever ABC island you can lay...or you can stop in PR
(Ponce has superb provisioning options, as does Mayaguez while the boat is in Boqueron) to enjoy 800#s and cheap USPS mail if you need something for the boat (boats usually have a systems issue by then...) and then depart from there for the ABC''s. The one scenario you want to avoid is heading out on your 4 day/450 NM run to the ABCs with a Depression appearing over the horizon.
For much cruising info along that entire route, consider buying a CD of the last 8 years of member Bulletins from the SSCA ($25). It''s available at ssca.org (go to the store, then Pubs, then look for the CD); the CD can be searched using Adobe Acrobat, which makes using it very easy. You''ll get a lot of info on the ABCs that otherwise are missing from the standard guides.
Good luck; I think you''ll have a ball.