1) A lot depends on your route. You would have to have a good, safe route to embark on this. We don't know where you live, so can't comment on that.
2) It obviously requires a large time commitment.
3) This is probably obvious, but at first it is going to be difficult because you won't be in the same kind of shape you'll be after doing it every day for three months.
4) It will also be harder in the beginning because of the learning curve on what to take, what to wear, how to handle sweat, how to handle lunch, how to handle clothing, etc.
5) If you can mix transit with cycling that would take some of the exercise burden off. It might make for a shorter commute, as well.