I disagree that it must be seen as a punishment; once you've attained your degree you no longer need to go to school, but going to school probably wasn't a punishment in the first place.

I guess it depends on your personal outlook.

c.f. notions of transcending for other possible interpretations.

I'm not a good Buddhist, so this is what AFAIK. Chance to be reincarnated as human is low, it's rare so we are lucky to be born as one. As human we have a chance to gather good karma and attain enlightenment, thus ending the cycle.

I think rather than punishment, it's more like a lesson. And dukkha is often mistranslated as "suffering", but in reality it's closer to dissatisfaction or unhappiness (sadness) rather than suffering.