hmm... perhaps I'm missing something.
If I want to drag horizontally I can drag (AND zoom) by just grabbing the timeline. I could of course also use the scroll bar at the bottom of the TV but it is fixed to project length and you need to click the magnify buttons for zooming so I ignore it. One of the most useful features is the Drag Scroll/Zoom timeline introduced in X2 but I think many people don't use it for some reason.
I digress...
If I want to scroll vertically then I just use the scroll bar to the right of the Track view. If anything what I would like is maybe a feature simialar to the Timeline Zoom where if I drag the scrollbar left/right it auto zooms the track height incrementally (and being able to disable that feature if desired). Maybe a "Track Snap" option would be cool too so when enabled as you scroll vertically the Track View snaps to the top of tracks (instead of halfway... again something that cna be disabled). The Auto Track Zoom thingie kind of does this but I find it a little awkward in general so this would be a better option for how I work.
Between those two things the only thing not covered would be diagonal scrolling that a "Hand Tool" could provide but the idea of having to switch tools or hold a modifier key kind of negates any real benefit of such a tool.
The more options the better really but it just doesn't seem worth the effort.
meh...
Edit: I just thought of a possible good solution... check it out.
Maybe instead of screwing around with hand tools or the vertical scrollbars maybe add modifiers to the existing Timeline zoom. Like as you drag Up/Down instead of Zooming Horz. you...
Hold Ctrl and it Scrolls Vert.
Hold Shift and it Zooms Vert.
Hold Ctrl + Shift and it Zoom/Scrolls Vert.
And I don't see any reason why you still wouldn't be able to drag left/right on the timeline while doing so (but my brain is all distracted and wacky so I may be overlooking something... just brainstorming).
So essentially in that scheme you can get ALL Zooming/Scrolling in ALL directions (even diagonally) by just clicking/messing around on the timeline.
Again... meh... just brainstorming.