Ok, I have installed the Start Menu and Koreader now works great. So, I had some sort of issue with advboot.
I had anyway to fix the Koreader touch coordinates to make it work with my Touch N905C .
Edit: I do have the "unresponsive if left idle for some time" issue, I'll try the fix here:
https://www.mobileread.com/forums/sho...&postcount=277
Edit 2: The preventfreeze patch solved my issue. So to sum up:
advboot+koreader+coordinates change doesn't work on my Touch.
KSM+koreader+coordinates change+preventfreeze works like a charm