WIP stands to Work In Progress…Rhino WIP will eventually turn into Rhino V6.
Should be able to get a copy from here…
Regarding your specific question about modifying a surface, a better approach in Rhino is to create curves that fit the points you desire then fit a surface to the curves. If you have a lot of this to do, it might be best to invest some time researching Grasshopper. It is a plugin for rhino that gives parametric-like features.