I will add ah custom Design, And, i go via WinSCP to /usr/share/retroarch-assets/xmb And wen i copy my theme become i the error you have no acess bla bla -.- this is no 1 and no 2 I will add ah cusum Loading screen wenn the Pi startet, we can add?
About custom theme, you need to put your theme in folder /tmp/assets/xmb/custom (inside you should have font.ttf and png folder). Then you can switch to your custom theme via Settings Tab > Menu > Menu Icon Theme > Custom.
For splash screen , I am not sure you can change it directly as system partition is read only, I think you need to compile your own Lakka.
its this the Complete Source? I
think not realy… And how can i compile the OS?
Is this with all Emus, just the Complete File for the OS? And can Custimize the Menue? i use aktuell the Nighly an have Bug with the German Laguane and will Fix This?!
I muss Recompile the Libretro?
Please say NO 
You can compile RetroArch only to see your update for German.
Can Close i Understand this 