1. Your best option is not to commute if you can help it. It will improve your quality of life. If you like Philly, I think several options are available. Look at pilot domicles posted on APC profiles and threads. Living at home will save a lot of expenses but unless your airline has an SD base, you have to consider commuting.
2. If you do commute, you are responsible to make yourself available at your base or origin of flight at sign in. You get there either by driving, flying on your own airline or else requesting the jumpseat on another airline.
3. The 2 hr call up is just that. When you get a call and answer, they have to give you a minimum of 2 hrs to get to the airport. Sometimes you get lucky and the flight scheduled is more than 2hrs away. So while on Reserve you need to be 2 hrs away. If you have a stretch of RSV days and commute you generally will be in base during that time unless you can drive it in 2 hrs. Also, different regionals have different commuter policies which you would need to explore.
4. What are your long term goals? Are you planning on ever getting a degree? Major airlines usually reguire a 4 year degree. However, if you go to a "direct flow" airline without an interview (Envoy, Piedmont, PSA) you might be able to bypass the college requirement. Considering your low time, a 6 year flow should not be an issue.
5. As far as I know none of the airlines you mentioned offer a direct flow.
6. The market is pretty good right now and at your age even if you make a choice and regret it, you can very easily swich to another airline without much issue since you have your age on your side. Just make sure you make it through training. It will be a big change and jump from your current position.
7. Good luck!