GMail & Imap: serious show stopper for most people in the world / a solution for the 'all mail' problem (at least for users of KMail)

Here are some information regarding the new imap-feature of GMail/Googlemail I couldn't find anywhere else:

1. Imap has a serious show stopper for most people of the world. Many special characters (e.g. German 'Umlaute' or East European special characters) aren't shown correctly. I hope this bug will be fixed really soon. If you write or receive e-mails in non-English languages you might consider to wait until this is fixed.
2. One theoretically nice feature of GMail with imap is that you can use it to upload all your e-mails originally written on a external e-mail client (like Thunderbird). Unfortunately all uploaded e-mails get assigned to the date of the upload not of the original date of sending. Since the date of sending is an important information uploading of old messages doesn't make sense to me.
   
3. You can't unsubscribe from the folders on the server. This implies that you have to subscribe to the 'all mail' folder. This really slows everything down if you use disconnected imap (which means that all messages are stored also locally). As in the web interface 'all mail' contains all your ever send or received mails (as long as you don't delete them or report them as spam). This means that you have to download everything twice!
   Fortunately there is an option for some e-mail clients to differentiate between imap-folders subscripted server-side and imap-folders subscripted local. This makes it possible simply to ignore the 'all mail' folder in your e-mail client while it still exists on the server.
   Here are my settings for KMail 1.9.7 (don't use earlier versions if you want to unsubscribe 'all mail' locally!):
   
   1. Go to the settings for incoming accounts and check the option "show only locally subscribed folders".
   2. Click with your right mouse button at your [GMail] or [Google Mail] folder and choose "local subscriptions...". Uncheck here every folder you don't want to see. Additionally to the 'send all' folder I also unchecked the trash folder because I use the local trash folder anyway. This makes sense as long as you don't need your deleted mails on several locations.

Update 20.11.07
Google solved the encoding problem. I still got seldom encoding errors but they aren't necessarily related to GMail.