
You mean you’d like to see something like this? (That’s a screen capture of the entire program window/monitor, not just a small part of the screen.) 
ZScripts cannot be used to change the interface.
As has already been pointed out to you, there are solutions available for nearly every concern that you have.
The trays on the left and right and the ZScript window can all be removed or brought back at a moment’s notice by clicking on the separator bar. The icons across the top can be changed to text. Thanks for sharing that, everyone!
You have even more power. The Float Menu can be made to appear or disappear by using the TAB key. You can also customize it by holding down the Ctrl/Cmd key and dragging interface items from the palettes out onto the canvas. You can then move things around at will, all by holding down the Ctrl/Cmd key. As a result, you can create the Float menu (and therefore interface layout) that works best for you.
For the matter of the task bar being covered, Alt+Tab allows you to switch between programs without minimizing. If you hold down the Alt key after pressing Tab once, you will continue to see the list of all currently open windows. TAB again will move you to the next one. Alt+Shift+TAB also allows you to move backward in the list. When you let go, that window will be opened.
For more information on customizing your interface, please visit Newbie Lesson One in the New Users section of the QuickLinks. It tells you everything you need to know, as well as explaining the entire interface in more detail. You have a lot of power available to you that you’re probably unaware of.
But by using these techniques, it is actually possible to have a canvas that fills nearly your entire screen, with interface items only present when you want them. It’s all a matter of preference.