Thanks twobob, NiLuJe, geekmaster, knc1 -- I really appreciated your help and pretty much got my working Kindle setup now
! The netcat/dd stuff works without problems over the WLAN funnily, so I guess I'll just be happy about that -- still puzzled about the NDIS/USB though. Also thank you twobob for the private/public key pair instructions, luckily I already had one which I used for my old VPS and Bitbucket/Github accounts, so I just pasted the public key part into the authorized_keys file while I had the USB mode activated and the connected via SSH to the Kindle
!
Am I mistaken in assuming that it is not possible to enable USB mode and SSH access at the same time? So that I can easily drag and drop files onto the Kindle via the USB connection and connect to the root shell per SSH whenever I feel like it?
EDIT: Just disable USE_WIFI_SSHD_ONLY probably, right? I'll check it.
EDIT2: Yep, thanks.
EDIT3: Well partly: the SSH connection freezes while it's in the USB mode, but it's better than nothing.