I recently purchased Movie Studio 15.0. When I opened it and imported a video I found there is no vertical zoom handles in the lower right hand side. I tried the "~" key and there was no change. Also while poking around, somehow I minimized my edit view and it too will not expand even when rolling the mouse wheel. I'm running a PC with Windows 7.
What do you mean by "vertical zoom handles in the lower right hand side" and what is it that has to be zoomed(in/out?).
There are + and - buttons to zoom the timeline in or out and using the scrollwheel of the mouse also zoomed the timeline with its contents in or out.
I think the OP means the change that was made in versions 13 and later. See e.g. https://www.moviestudiozen.com/forum/movie-studio-platinum/250-scroll-bars-to-the-right-of-the-timeline-disappear. The thread includes some of the solutions to turn that scroll bar on again. Read more in another thread starting from this comment. The last comment there also includes the link to the devs' argument for the change.
And if by minimizing the edit view you mean that the tracks are minimized, the Movie Studio basic (non-Platinum) version does not have the options or buttons to restore track heights (even though the online Help file so says). "Drag the bottom of Track Control Box(es) to make the track[s] taller (the scroll bar will also return)" as the first link advises.