We only spent 32 nights in Majuro Atoll (in 4 visits)--the rest of the time we were out cruising and diving. We used Majuro, and to a lesser extent Kwajalein, as a provisioning and social hub, and that worked our pretty well. You can get provisions, mail, cell phone and internet in both Majuro and Kwaj.
We had easterly winds from May-July and flat dead calm for all of August and September. The locals all said that it was unusual to have had as much wind as we did in June/July, and to have such a prolonged period of no wind in Aug-Sep.
If you've stumbled on our blog and haven't found our Marshall Islands Compendium, you can find it here: http://svsoggypaws.com/files/index.htm#Marshall%20Islands