If it were me, I'd find a cheap, mid 80s steel roadie, and use that for the commute. It won't be as much of a thief magnet as your Jake, and it will provide good reliable transportation. It will probably have horizontal dropouts, thus offering options such as fixed gear or singlespeed. There will probably be enough clearance in the calipers/frame that you can run 35mm knobbies, and make it your "pit bike" if you get that far. If it gets stolen or bashed up, you won't care, because you only have $150 into it. Feel free to race your Jake with abandon, knowing that your trusty Nishiki/Raleigh/Centurion/Peugeot/etc. is ready to take you to work on Monday.
That's what I would do.