There is much better food in Philly than cheese steaks. Yeah, the liberty bell is meh. There are also a lot of really cool but less famous places scattered throughout the city. Some must-sees: the Mutter Museum (a collection of medical oddities) and the UPenn archaeological museum. And the art museum is really pretty awesome.
Sure there is, but you can get exquisite food in any major city. If you are going to experience Philly, you want to eat something that is distinctly Philadelphian, so pick up a soft pretzel, some water ice (aka italian ice) and a cheesesteak.
The UPenn museum is quite impressive. I'm not much of an art aficionado, so the art museum did not really appeal to me. I've never been the Mutter Museum, so I can't speak to that one.