As a reference here is a list of gestures and their default actions:
https://github.com/koreader/koreader...eader-Gestures.
The kindle thingy cannot be avoided, AFAIK. It is just software that still runs while KOReader is in the foreground. Never happened to me years ago, when I had a Kindle (fw 5.6.?) so it should be another change in fw which happens to reduce the QoL of 3rd party app users.