On launching iClone, the first thing I want to do is maximize the screen space, but there's no way to do it.
Both Windows Title-bar at the top, and the Windows Task-bar at the bottom, are a complete waste of space.

It would be nice to have a toggle button for Full-Screen mode

Not to mention a way to close the left and right side docking panels with a button instead of having to re-size them all the time...

I know what you mean, and I get sick of having to adjust that divider in iClone5.5 PRO content manager all the time!
I wish it would just save the position cause it's really annoying, I hope they fixed it in iClone6.

With the 6.4 update, you can close everything but the title bar. Then you could save that as one of the presets. The Task bar is a Windows thing, and can be  set to auto-hide.

This is not the same thing at all.  The docking panel on the left cannot be closed, or more aptly stated, it cannot be minimized. Mosr current and modern UI's allow for docking panels to be opened and closed, like a drawer.  iClone does not do this, so you must constantly resize the panel smaller and larger to either view the contents, or to expose more of the screen.  This is what I, and some others, would desire for the UI.