Short Visit to Philadelphia (Pittsburgh, York: best neighborhoods, hotel, home)

[ML North]

Hi everyone and greetings from the Pittsburgh subforum.

I have some free vacation days to use before the end of the year, and I'm considering using them to take a road trip out to Philadelphia, Jersey, and perhaps New York City. I'd probably spend two or three days in Philly before moving on and will likely be traveling alone. I'm 24.

I've done some research, on this forum and other places, and have narrowed down some of the things that I'd like to do, but I wanted to specifically ask for advice regarding the following:

• Sleeping Arrangements
  I have some friends in the City with whom I may be able to stay, but if this isn't an option, I'd consider sleeping in my car. Can anyone recommend an area in which I'd be able to do this without being fined or bothered? Is this a really bad idea? A hostel would be a viable option, but I'm not really looking to tent up with the "Occupy" protesters. If hotel is the only reasonable option then that's fine, but it would be my last choice.
  
  
• Home Base
  So I'll be driving into the City, but would like to remain sans-car during my entire visit. I live in an urban area, travel frequently, and generally feel comfortable in most areas, so convenience and parking costs would be the driving factors. Can anyone recommend a neighborhood, preferably with access to a transit hub, that I should call home for 36-48 hours?
  
  
• Transportation
  Admittedly, I'm a meticulous planner. Can I rely on this map, used in conjunction with Google Maps, for navigation? Also, are there any transit routes that I should avoid?
  
  
• Neighborhoods
  So this may or may not be an unusual statement, but I'd really like to see Philly from a variety of angles. I want to leave with a well-formed impression of the City, so I'd like to see the best neighborhoods, the most usual, and potentially some of the not-so-nice areas. Can anyone recommend some neighborhoods that I should see?
  
  
• Entertainment
  An excellent open-mic, acoustic cafe, comedy club, or blues club would be definitely be something that I'd be interested in checking out. World Cafe Live, Ortlieb’s Jazz Haus, and a few others came up on some of my searches, but I know that the best places are often the most difficult to find. Where is the best local talent?

Thanks in advance for the advice, everyone, and I'm looking forward to visiting.