With multiple monitors, can I pick which one an application will load on?
Not with the default Apple Spaces.

There is an alternative, though. CocoaBots makes a small app called Hyperspaces which builds upon the default Spaces and adds a bunch of cool features. Multi-monitor support is coming to their next release.

http://thecocoabots.com/blog/post/148/hyperspaces-104-and-the-road-to-11/