Term reference on node edit to ALL vocabularies
The Vocabulary reference module might help you, but it doesn't even have a dev release.

A more involved solution would require adding a term reference field for each vocabulary, then placing a "controlling" list field on top of them, with an allowed value for each vocabulary. 

You could then dynamically show and hide the right term reference field using the Conditional Fields module.

The module handles required fields, so you would be sure that one term is always selected.