Java EE (Java Enterprise Edition) General Discussion

I'd like to start learning JSF 2.0, however, before I begin I have a few questions I'd like to clarify:

1. What are the differences between the reference implementation and MyFaces ?
2. Can jsf 2.0 with reference implementation or MyFaces be deployed on any servlet container, i.e. tomcat/jetty, or must it be deployed only on a Java EE compliant container?
3. How difficult is it to create custom tags?
4. Is it possible to use *Faces+ (i.e. PrimeFaces, RichFaces, etc) with a javascript library like jquery or yui? Are any conflicts created by doing so?
5. What are the biggest limitations/shortfalls (if any) of JSF 2.0?

Thanks.