@sioc about
1) yes. Read the thread of KSM.
2) Yes, you could try to help debugging
that issue. Because it only happens irregularly, it is hard to fix. It bugs me, too!
3) Tap the top line of your reader: that is
toggle frontlight on in KSM. I think you could also configure KSM to enable frontlight by default. At least, I think that it used to bother me that it was on in KSM without me wanting it.
4) Actually, the fast workflow is exiting koreader and do whatever you want in KSM and returning to koreader. ***
5)I don't know what changed, but nowadays I go a week before having to recharge it, while reading for hours each day. I kind of forgot about this hardship.
EDIT:
***Nowadays I have removed the internal SDcard for a 64GB one. I can leave USB enabled without bad effects and run koreader. So I can just plug it into my PC. Copy the files and
access them through koreader without ever leaving. This doesn't work if your library is on your external SDcard, of course. After experimenting it appears this actually generates an error when opening such an epub-file. I'll look into it and try to fix it: It would be really nice to have that working.