Ok, I've chatted with an iMate's technician.
The answers have been:
(1) Apple and Microsoft are competitors, and therefore Apple does not support a Windows-Mobile-based phone (strange argument, for e.g. HP and Lenovo are competitors too, but Lenovo supports HP's printers! - maybe that's not the most fitting example, but You've got the idea, haven't You?);
(2) You can get a third party SW at Mark/Space;
(3) uh, yes, You're right: Mark/Space (and PocketMac too) doesn't support WM5 yet;
(4) ah, altough disappointing (verbatim), yes, there is no way to export Your contact from the Address Book to the KJam.
Now I'm gonna try to syncronize my previous phone (Nokia 6630) with iSync, and than syncronize my Nokia with my Pc (yes, I admit it: I've a Wintel too...but I hate it!), and finally I'll syncronize the KJam with Outlook.
I fear it will be a mess, but I'll try: I guess there's no other way out!