Here's a bit of an idea. Have a requirement of at least one job at 60 in order for any sort of jump potion to be used. I for one welcome the idea of it, at least for me leveling alt classes is a chore and I always end up going back to my max level job rather than try to level another job. For me at least, the level grind from 1-50 feels painfully, mind-numbingly slow, and the ability to at least skip that I would wholeheartedly welcome. As for learning to play the class, I really never got that from leveling, it was more looking it up after the fact rather than while leveling, would be nice if job quests were a bit more comprehensive in teaching each class. Anywho just my two cents.