Kind of a 2 part question:

1)       Is there a way to scroll through the feature tree without having my mouse cursor over it?  I know there is arrow key navigation, but I still have to pick the roll back bar first, often I roll a little zoom/pan/rotate the display and then want to roll the tree some more.

2)      I have a logitech keyboard with a scroll wheel on the left end of it.  Ideally I would like have this function as a feature tree scrolling only (regardless of my mouse cursor position).  Currently it will operate exactly like my mouse wheel, so only scrolls the tree when the cusror is above it, otherwise acts as a zoom.  Is this possible?

Basically I want some way to rotate/zoom/pan the view with my right mouse hand, and roll the tree with left hand.  Do any of the space navigators, or 3D mice allow this?