For both buttons forward, look at the Kobopatch thread. The latest formal release was:
Instructions for patching firmware 4.38.21908. Download and unzip that version into a directory on your computer. Download and copy the kobo-update-4.40.23081.zip file to the src directory. Then change the version references in the kobopatch.yaml to:
Code:
version: kobo-update-4.40.23081
in: src/kobo-update-4.40.23081.zip
.
Locate the libnickel.so.1.0.0.yaml file in the src directory and change the no at the end of the
Both page turn buttons go next: no line to yes.
Run kobopatch.bat and if all was done correctly, you will have a KoboRoot.tgz file in the out directory that can be copied to your LC's .kobo directory.
As for the screensaver, create a directory called screensaver (case sensitive) in the .kobo directory and copy the images you want to use as your screensaver into that directory. In Settings => Energy saving and privacy, make sure
Show current read: and
Show book covers full screen: are checked. I haven't bothered with changing the resolution between my Sage and Libra Colour but in theory, 1264x1680 would be best for B&W images while 632x840 would be best for colour images on the Libra Colour.