My dad is someone who has taught full time in the field of theology... except for when he was going to Law School, which he paid by teaching theology in their University.
If my son wanted to "go into the ministry" I would absolutely "insist" on the foundation of teaching. :) So, for pastoring/teaching, I would suggest learning Latin, Hebrew and Greek as the base... with everything else :) Then I would have him graduate with a minimum of a Masters and hopefully a Doctorate. I believe it's best to get through schooling.... and not "skip any schooling"... :)
Going to a great Seminary, with good doctrine being taught is essential. I wouldn't suggest anything less :)