I think owning a burm or retic shoud be live driving a car. Some are ready by the age of 16...this would obviously be the teens who have had a strong interest in herps and show they are able to deal with such a large animal....
But for those who aren't ready to drive a car...they have to take the test again, and again and again until they prove they want to drive that car. A car can also be a lethal weapon and I believe burm/retic sales should reflect this sort of structure. Those who are ready are ready, and if not, then you can't have one. If a person truely wants one to care for and not because they are "cool" then they really would have no arguement to this sort of thing. (making a license for minors a must)
The only real problem I see with this is enforcing it, and giving out the permits.