I live in South Philly, right where you would be staying it seems. I bike a lot - both kitted up for exercise and on a singlespeed to get to bars and what not. No real issues, just need to be aware of your surroundings and if you give cars respect, you usually get the same back. And just watch for car doors opening. I'm not afraid of riding in traffic. I obey all rules for the most part.

Riding at night usually less traffic yes. South Broad, there is no real reason to even ride on it. Bike lanes on Spruce and Pine Sts make east and west riding easy. And mos of the north-south numbered streets are no big deal.

There are bikers everywhere. Cars are use to it, more and more.

If you want to do a longer ride, the Schuylkill River Trail is nice and I can give you specifics on that. Can do up to 60 miles roundtrip...

Doug