I fully agree with the concept of raising the barrier to entry and mentoring
Raising of the barrier to entry can be done through some kind of
online testing if possible ( I dont have much idea about them). A
person who is applying for Fedora ambassadorship should give that test
and have to clear it before moving to the next round that can be a one
to one irc session .If both the sessions are satisfactory the person
will be selected for a 3-6 months of probation / training period where
he has to fulfill some goals to become a Fedora Ambassador.