Many additional questions not addressed on this site can be answered in the help menu within the FLEx Program.
For a more in-depth look at what FLEx can do, check out the demo videos from SIL. You can click here for the whole library of videos.
A website for training for different tasks in flex. Clicking on the bold text for a lesson on this site downloads a word document walking you through the steps of a task.
You can report bugs by emailing: FlexErrors@sil.org