Hey Poprocket, the front seat is available to revenue passengers, so unfortunately if it's booked to 9 you'll get left at the gate as a jumpseater.
Weight and balance really shouldn't be a problem on the shorter routes unless you really get Bubba and his wife Bertha packin' it in there with the kids and 300 lbs of luggage. All of the aircraft are modified to increase MGTOW and MLW, but we do use actual passenger weights, not standard. Generally if everyone's weight averages 200 lbs or less, 9 people plus bags is fine. The only snafu might be on the longer north country EAS routes during the winter where pilots tanker fuel out of the hub into the stronger headwinds. That becomes an issue on the SLK, PBG, RUT flights normally. Those weight restrict to 8 quite a bit, but most pilots are good about holding off the fuel order if it's booked to 8 or 9 to ensure that everyone gets on.
Anyway, let me know if you have any more questions. We're always happy to have jumpseaters.