Hi Pearlece,
As Ed already mentioned, all of your questions are very, very high level. Workflow Foundation is some kind of platform for building of broad range of Workflow applications and solutions. WF is build almost at the Language level (just a bit higher) . On the other side all “solutions” related to your questions can/should be implemented at the application level.
WF like many other Microsoft technologies is not a product. It is a platform which gives you ability to implement appropriate business requirements.
If I would have to implement your requirements, I’m not sure that I would even implement all of them based on WF.
Hope this gives you a bit better understanding of WF.
Damir