Thank you so much for the replies. The first two issues are fixed! thx
That what I was trying to ask about Notification Settings : I downloaded DashClock apk. When it comes to set the widget you can choose some extensions, like for example "what's app notification". Once did that, the line that is supposed to have the notifications says "This extension requires access to notifications, click to configure".
Well if I do this it simply bring me to the android main general setting page, where obviously there's just wifi/bluetooth and other connections option.
The same happens with every single app that requires me to enable access to notification (Nils, AppOps, ecc ecc)....under options selection like "click here to configure" or "click here to give permission", every apps bring me to general setting.
The only thing I've noticed is that under "device setting" there is "accessibility" and this is where I can see "services" and all the apps which need some sort of notification permissions are listed. BUT again if I flag them nothing change.
I hope to made my self clearer

, english is obviously not mine main language