Converting only eligible opportunities to projects
The concept that you can covert an opportunity to a project no matter in what state the opportunity record is is flawed. As an example, you can convert a lead into an opportunity where the opportunity has certain mandatory fields. But without touching the opportunity and leaving the mandatory fields empty you can convert this same opportunity into a project. There should be some way to set rules that must be positive before an opportunity can be converted. Seem very logical to me?