Everything went OK, except:
– in the partition manager I’ve accidentally messed the mount point for my old /home and /data drives -.-”
– like an experienced Linux hacker I’ve downloaded the nvidia driver binaries a gcc, make, kernel-source / header and started to cook up a new driver, the result was: a totally empty grub loader. After a few kernel panics I’ve started the system manually from grub’s command line thanks to this guide: http://en.opensuse.org/SDB:The_Boot_Manager_Grub. Conclusion: wiki 1st.
There were no problems with openSUSE at all.
*PEBKAC (“Problem Exists Between Keyboard And Chair”)