i was looking at the strip using the geck and i noticed that it is the same world in each section, so would it be possible to remove the doors of the gates that separate each section of the strip?

It might be theoretically possible, the presence of a loading screen makes me doubt even that, but it would probably be a bad idea.

The engine has real trouble any time there are more than, say, 10 or so animated NPCs onscreen at any given time, originally the strip wasn't split up, it was segmented at some point in development because of performance issues.

Already been done, search the mods forum.

Do you mean like http://www.gamesas.com/index.php?/topic/1144657-beta-the-strip-open/ Tarrant started it, and it looks like someone is trying to complete what he started. Don't know how successful he/she's been yet.