Thanks Jim and Zocky. I was already suspecting that it isn't possible...
I knew that I can switch off toolbars, but this isn't what I want. Just to give an example: The "Preview" toolbar has icons for new preview, modify preview, clone preview, show preview, next view,... it keeps going on. I never use any of the icons except new preview and modify preview. The rest just consumes space with the effect of moving in other toolbars important icons into the ">>" menu. I could use a second or a third row for toolbars to make all icons visible, but this cuts into my workspace which I can't spare.
Tahir