Around the venue can be a little sketchy. Whatever you do don't follow the black guy who tries to waive you down to a "parking lot" to the left right before the venue entrance. They send you down about 5 blocks then some shady dude will try to charge you $40 (then probably rob your car when you're not there). If you're driving, try to get to the venue a little early and get in the main lot. If not, try going down a block or two there's some street parking. As for food, the other poster was spot on about Reading Terminal Market (think farmers market on steroids with a bunch of little walk up food counters) and Dinic's Roast Pork is the best. Also if you're in town before the show you can always check out South Street. Lots of places to eat/shop there. Jim's on the corner of South 4th street is top notch for Cheesesteaks. If you're going to Jim's the line will probably be out the door & wrapped around the corner, but the wait is worth it. They let you BYOB there and if you get your steak walk to the back of the restaurant near the bathrooms and there's a stairway that takes you up to a 2nd floor eating area with great views of the crazies on South Street! You can also leave out the door at the bottom of the stairway so you won't have to fight your way through the crowd in the restaurant on the way out. Pat's and Geno's are nice because they're 24hours & usually have a pretty eclectic crowd. I prefer Pat's but there are definitely better steaks around if you're eating during regular business hours. Don't get me wrong I've eaten many a Pat's cheesesteak and they are good (just make sure you know how to order what you want before you get to the window). Cheesesteaks at the 1st window, drinks and fries at the 2nd window.
The correct way to order: Wiz witout = Steak with Cheesewiz no onions. Wiz wit = Steak with Cheesewiz and onions. Then you can substitute different cheeses like American wit = Steak with American Cheese and onions. If you want marinara sauce on the steak it's called a pizza steak. There are peppers on the counter behind the window along with napkins & utensils.
If you've never been there I highly recommend checking them out just for the spectacle. But for my money I'd rather eat at Phillip's Steaks, maybe Nick's Original Roast Beef, a Primo Hogie (Italian sandwiches), John's Roast Pork (which is hardly ever open), or *Dalessandro's in Manyunk (a little outside of the city but my favorite). As for bringing in party favors at the Electric Factory. In the past they have shaken people down pretty hard. I recall a while back having to take my shoes off at the door for the bouncers to search them. Haven't been there in a couple years but you may want to get creative if you need to bring something in under the radar. One thing the Electric Factory doesn't lack is energy. The place will be rockin. The sound is good and loud but don't plan on too much dance space. Should be a great time.