Sadly, I found no solution even 4 months later. And even more sadly, I didn't even get one reply here.
I'm trying to put all the re-mount commands into a script to help me after reboot.
But I haven't found a fix for the access permission problems of the root folder of the shares.
Can anybody tell me, on a normal, non-encrypted system, what are the permissions of the mount points, the top level shares and which user actually performs the mount on a normal system startup?