I think the problem arises because the rotate function seems to pivot on the center of the view or perhaps the center of the build area (I'm at work so I cant test for sure), which is well above the platform. When something you want to see is small it is very easy to rotate it out of view.
However as stated earlier, you simply need to pan in order to maintain the area of focus in view.
This often requires doing things is smaller steps. rotate a little but not loose the part, pan to center the view, zoom to enlarge, repeat again and again until you are seeing what you want where you want.