8)
If the cast and crew are having second thoughts, then maybe their second thoughts are an indication that something should be restructured?
You know, restructuring in terms of story, character development etc.
As a producer and/or director, you're going to have to utilize different channels of communication in an orchestrated manner to keep everyone convinced of the production's significance. Since they know you personally, they should be more receptive, but if the story sucks, and they don't relate to their characters, you'll have to drag them through the production process kicking and screaming. Keep them together, and on the same page with you, not against you.
Luck...