Thank you for your reply, and here is my update:
On the first issue with the cooler - I have waited for the most recent FOTA (17.0823.2007.58-0), installed it, tried clearing the Armoury Crate app data, and it didn't work. After that, I've restored the phone to its factory settings, and the ventillator still doesn't spin. Should I wait for another update, or should I send the cooler to a service center?
On the second issue - I understand that it takes time to introduce changes like the opportunity to hide the navigation bar, but I hope that this feature is going to be added in one of the following updates, as it is one of the most important details for me in the UI. If you have any information about this topic, and of course are able to share it, then I would be very happy to hear it.
On the third issue with the darker tones - I have to say, that after the most recent update it looks noticeably better, at least on Youtube.
On the fourth issue with the flash, again, I understand that it takes time to introduce these small changes, and this one could not even be made, and the additional unlock animations have got no connection to the flashing light coming from under the finger.
There is one more small weird thing that started happening on my phone since the last post - when I call someone or answer a call, the numpad appears automatically, like on the screenshot attached below. After about 30 careful retries (including 5 after restoring factory settings) I am positive that I'm not just clicking anything on the screen.