Can you rappel directly into the subway, or do you half to take the complete top down or bottom up route? I'm looking to cut a little time off the trip.

The fastest way to get to the Subway is probably coming in from the top, standard route. Going in from the top is much more scenic as well, since most of the good parts are above the Subway, though both are worth the trip.

There really are no shorter ways in that are practical. Sure, you could bushwhack cross country through rugged terrain from the north and then rappel directly in, but it would almost surely take longer and be more difficult than using the standard route. You would be missing most of the good stuff as well.