I don't think being able to glamour equipment should be "free game," either. As I have said before, the player should still have to earn the right to glamour those additional pieces of gear. If the player wants to glamour a piece of tank gear on their caster gear, they should be required to have the necessary job leveled to equip the actual piece.
All of the other restrictions would also still apply. For example, a piece should have to be equal or higher ilvl to what it is being glamoured as.
By that logic, I don't think that AF should be restricted either. If I have earned the piece, and earned the necessary right to equip the piece, I should have the additional right to be able to glamour that piece to other jobs.