Kontact and different kolab issues

Hello,

I'm just migrating from Thunderbird to Kontact. But I have some problems  
with the groupware functionality.
1) First of all: Why do I need a Disconnected Imap account to use the  
Kolab2 feature? It took me ages to find this out, so I could enable the  
groupware feature.
2) The XML files, I copied in the synckolab folders, I created with  
Thunderbird, are accepted and interpreted from Kontact. But I could not  
synchronize these folders with my IMAP server, because it do not allow me  
to create subfolder in my inbox (If I create subfolder with thunderbird,  
it is located at the root position afterwards). Could I somehow change the  
location where the kolab files are saved?
3) In Thunderbird I had a different addressbooks and calendars for private  
and business use. With synckolab I could separate this informations in  
different imap folders. Is it somehow possible to manage different  
addressbooks and calendars with kolab from Kontact, too? It would be also  
ok to manage private and business stuff with different identities. But as  
I understood it is not possible to activate groupware for more than one  
identity.

It would be great if someone could help me with this issues so I could use  
Kontact instead of Thunderbird. By the way, I'm using Kontact 4.3.2.

Many thanks,

Fabian