That sounds like a request that would be better suited to the Kodi forum.
Regarding the mouse I don’t believe there has ever been a way to adjust the sensitivity in Kodi. There may be a way to adjust this in Debian (don’t know, never tried) but mouse support has never been great with Kodi as it is a media player that is designed primarily around using a normal remote control. I use Kodi on PC’s as well and I end up using the keyboard to control it most of the time which I find works better than the mouse.