Upgrade Install * $149 includes importing new files afaik; i think it can cost more on larger installs.
You can limit user access to pm's by adjusting the "Accept Private Messages?" field in their profile.
You can "disable" the portal, and users will go directly to the forums, or you can link to the crfm page; but when the portal is enabled your users will go there by default when accessing yoru forum without crfm in the url.
and yes it's possible to use the same directories, however during yoru import you'd want to use a new directory, then change the directory name once it's installed.
