[Zope-CMF] would you use CMF to meet this requirements ?

[pdsnr@yahoo.com]

Hi,
I have to develop an portal with the following requirements:

- closed user groups: user groups are maintained in an seperate back 
office application and transfered each x days / weeks, new users 
cannot create an account on their own.
- each user group has its own area (folder ?) with specific access 
rights
- one user can be a member of more than one group
- users may have different access rights per group, i. e. no access 
to group 1 documents, read access to group 2 documents and upload-
capabitlities for group 3
- single login: a user should login once in the system not on an per 
group basis

It's obvious that it is no problem to develop an application with 
Zope that meets this requirements. But I like the idea to use a 
framework and I wonder if CMF is a good starting point.
What do you think about it ? Could you give a short description of 
the necessary steps, if it would be done with CMF ?

Peter