Can't really see the point of that zsnake effect then, just more fancy rubbish.
Zooming using the mousewheel is good for small zooms, but I find using the scrollwheel too much is bad for my finger, mouse panning is usually better (click, get compass thing, move mouse). Dragging the scrollbar ends means only dragging 1 screenfull max. The only problem I can see is if you want to zoom in centred, having to drag one end of the scrollbar then the other would be silly, maybe a modifier+drag on the scrollbar would zoom it centred on the centre/click position.
The problem with the ROS4/Phoebe drive icons is they look too similar, a floppy disc would be better for the floppy drive, cd for cd drive, generic box for harddrive I suppose.
Mouse panning works as well as I imagine a trackerball would. You'd still need scrollbars so you could tell how much of the document was on screen.
I tried using MouseAxess once, but it thought I wanted to menu-drag a window when I wanted to click menu and move the mouse to the menu option I wanted very fast. I couldn't see any way to turn off specific features so it was removed.