I think I know the PI GUI pretty well and I've never seen anything like that.
For any process you can make a process icon as you suggested. You can also drag a process icon from the history of an image. For commands in the process console you can use the up-arrow to recall previous commands (the command line is very powerful if you're not a GUI person.)
The specific case you mention of "zooming" is achieved by clicking and dragging the name of an image and dropping it over the name of another image. If the two images have the same geometry this will result in the second image panning and zooming to display the same region at the same zoom level. This also works for previews.
I don't find the speed of the PI GUI to be a problem. It's usually the wetware that's slow
Cheers,
Rick.