Sweet, tried it once again and got to done, Tomodachi Life's installing now.
- Menuhax 2.1 on autoboot (type 2)
- started FTBrony, immediately closed it (2x B)
- started FBI, spammed A (since some people succeeded by that I thought "why not")
- saw the log for a second with "Done" at the end
- tried installing Tomodachi and now we'll see
Oh yea, sysinfo or something, right?
o3DS 10.3 EUR
Update: installed successfully, downloaded the update for the game without probs. Gonna try SSB later as well.