While tooltips can obviously be very helpful, it would be nice to have more options. Some ideas would be:
1) Ability to adjust the amount of delay time before the tooltip appears while hovering with the mouse or stylus.
2) Ability to adjust the amount of time that the tooltip remains visible.
3) Ability to toggle tooltips on or off entirely.
4) Perhaps consider a separate tooltips window or panel that could be docked or floating. No matter what tool or function you hover over, the appropriate tooltip would always be viewable in this same window, which would also help prevent tooltips from obstructing the view in other areas.
I feel that #3 is the most important, to have the ability to turn off tooltips