1) Knowing which book you're reading is the job of your reader software. Anything to change the cover image would have to be implemented there. I'm not sure who uses Neo Reader vs. 3rd party. The default images are in system/media. The replacements are in:
Code:
/data/local/assets/images/shutdown.png
/data/local/assets/images/standby-1.png
/data/local/assets/images/standby-2.png
/data/local/assets/images/standby-3.png
(I don't want variable sleep images. Also, I use a cover.)
2) The dual sliders for warm/cool is a bit convenient. I knocked out a little app that uses brightness/color. I usually just leave the brightness at 30% all the time. If it gets dark then I notice it. It doesn't seem to hurt the battery usage enough to care. (Auto color is not my thing.)
3) There are developers working on stuff. Their goals are probably different than yours. My #1 gripe is removing Onyx short/long press processing so that any button acts on press (rather than on release). Being rooted you can disable a lot of stuff.