I don't think there are any web sites that will tell you how far attractions are from your hotel. If you post what hotel you are staying at someone might be able to give you a general idea on how far certain things are from your hotel. As far as I know there is only one company that does shuttles to Shell.
http://www.shellislandshuttle.com/ Not exactly my idea of a good deal. It costs $11.50 for the shuttle ride, but it will be worth it as long as you pack the things you need to hang out on Shell for a few hours. There are a ton of charter boats that do deep sea fishing. I know I have seen some that charge around 40 bucks for a 4 hour charter. I am sure someone that lives in PC could help you better with that though. Here is a site with a bunch of companies that do deep sea fishing.
http://www.panama-city-beach-fla.com...g_charters.htm Good luck!