On the stair issue all I can offer is to use the work around that David suggested.
On the orbit function: This seems to have changed for the better with the update to build 2420*. Are you up to date on your hotfixes?
That said I don't recall ever seeing the behavior you mention. It used to be that the view would orbit around the center of gravity of visible and selected elements. This was OK but was troublesome if a large site model or slab was selected while navigating in a tight view.
The present behavior seems to reset the focus of the orbit to the center of the current view each time it is used. I find it very fluid, predictable and easy to use.
Perhaps the problem is peculiar to your set up. Please add your system info etc. to your sig line.
* BTW a new hotfix update to build 2523 has just been posted.