I can agree with one thing which is remove unused system apps to get more space. But other than that I don't agree with you.
The sms app that you installed after removing the default sms app, what was additional features you were looking for? Were you able to send something which can not be sent with the default one? If yes, do the other party have to have the same sms app to view those messages? or their default messaging app can be used to view those message?
If you remove the passcode thingy after rebooting your phone, where is the security?
If you want to shut down cpu's 2 core's when the phone is in idle, what is the use of it?
I am not sure about the sound quality once you customize sound on your phone.
Even you think some system messages are stupid in Android..
One thing still I cannot understand which is, why those companies do not release those phones with rooted access even though they know that people can root their phones. (They are talking about Android is open source, but with some restrictions.) Even Google Pixel is not coming with root access. Why?
At the end of the day people like you can do the Android customization. But not everyone, and still they have the same reasons like you do to prefer Android over iOS.
Thanks bro...