The hub is Dulles, all the flying is fed to the United sytem through there. Ft. Wayne remains as the maintenance base due to low costs for real estate. Ft. Wayne is still a crew base but it's down to about 5 or 6 lines and about 10 crews so the majority of the folks are in DC. In the wee hours of every morning, a Ft. Wayne crew takes an airplane to Dayton where it then starts it's day and goes to Dulles. At night, a returning crew dumps off the last pax in Dayton and repos the plane to Ft. Wayne for it's MUCH NEEDED maintenance work. There are reserve lines in both cities.
As far as getting more Saabs, well let's put it this way, they had about 18-20 flying 6 or so months ago, now they are down to about 11-13 with some sitting spares and some doing charters. So to me that's not a good sign of any future growth. Several cities that had Saab service now have rj service and that will only continue. So, staying the course for now, who knows about 6 months from now. Don't drink the company kool-aid about any jets either, heard it for several years, still not one there yet!
Schedules are mix of 2,3,4 day trips along with some day trips. IAD seems to be mostly commutable with some exceptions.
I'm sure when it comes to commuter airline world, SA is no better or worse than any others out there. Once the promise of a quick upgrade brought masses to the doors, but now that pipeline has just about dried up. Will they be here for the long term? That's a good question! Being treated as the bastard step-child of Wexford/Republic/Chq. can be trying at times.
Best of luck in the pursuit of your career!