1. Michael didn't tell Vitelli "not to tell it to anybody else". He told that there are some certain people, who'd pay a lot for such information. Certainly the villagers were not among them.
2. There was a traditional wedding, nothing special. It couldn't in itself bring him into the light out of "that part of the island".
3. I'm positively sure that the attempt on Michael's life was planned long before he met Apolla. Fabrizio was not planted but cleverly used. I posted once a thorough analysis of the whole affair in this thread. Scroll down for a veeeeery long post.
4. I just wonder - Junior, why do you always type in bold? Is it a conscious decision?