Well, I had a look at the script and here is an update. 
Unzip the zip file into your ZStartup\ZPlugs folder. If you’ve installed the plugin before then the three new files should overwrite the old (the names are the same):
AdjDrawSize.zsc
AdjFocalShift.zsc
AdjZInt.zsc
Hotkeys as before. If you don’t want any of the hotkeys simply delete the relevant file.
In this updated version the Draw Size, Focal Shift and Z Intensity are all indicated in the NoteBar at the top of the UI. This helps if you use a maximized workspace.
(–E-- : I have also included a line of code which may solve your ZIntensity problem - let me know!)
A tip for those who work with a maximized work space:
To stop the canvas being resized when you use the hotkeys (or many other plugins), drag the bottom canvas resize handle until it is almost at the bottom - about 5 pixels is right. Then store your UI configuration (Ctrl+Shift+I). The canvas will now remain at this size.

I hope you find the update useful,