The viewer does not appear to be linear for me, the harder you flick the faster it scrolls. It does have a scroll bar but you can't grab it as a handle.
As before, which editor are you using (i.e. did you opt into it in the settings)? The beta one has proper scrolling and doesn't keep bringing up the keyboard.
This is the version of the app, yes. You can upgrade to the released 2.9 if you want but there are issues in getting it published to the play store - What's new in Joplin 2.9. This version has a lot of QoL improvements to the mobile app.