If you want to request something write to GPSoftware so they can consider it and add it to their to-do list.
I agree.
I'll answer here but please ask unrelated questions in new threads to help people searching the forum for answers. (More on that in the FAQs.)
I don't think you can disable automatic scrolling of the tree, except by locking the tree so it does not respond to directory changes at all. I agree that it'd be better if it scrolled only when really needed (and kept the icons in view instead of scrolling so the name starts on the left edge). Although I turn off the tree completely myself, I filed a suggestion along those lines a little while back but I don't know if it'll be implemented.
You might find it helps to use a separate tree for each file display instead of a shared tree, though. The option for that is in Preferences - Listers Folder Tree.