In Bioshock when you beat the game can you still roam around rapture?

Question

I've been playing the game and I don't know much about it but something I really need to know is 1. when you beat the final boss can you still play around? 2. When you're searching for the final boss and hes taking you're health can you roam around the city, but will he keep taking you're health? (Even if you're going in the other direction?) If anybody has any questions about this description email me or whatever you can do with "yahoo answers."

Answer 1

Absolutely!  Yeah, once you beat it you can still roam.  

However, I'm unsure that you can leave the arena once you initiate the final boss battle against the super easy final boss.