I know that I can use the transpose tool to scale/move/rotate my subtools, but it is not useful when I want to make precise actions like rotating in exactly 90 degrees. There are sliders for scale and position in the Tool->Geometry menu, but not for rotation.
Yes you have rotate in the deformation palette. All those modifiers will change from 0,0,0 point so you can use SetPivot ClearPivot in Transform palette to use in your sobtool if it weren´t centered
Additionally, after rotating by given angle you can “snap move” to get subtool back on the right position - this is one of the new functionalities in my “ZBrush Surprising Tools!” plugin…