When you squeeze the view down on a video clip pan/crop it doesn't squeeze the video it just cuts the view. Can you make it so when you click on the pan/crop in the video track and scale the view around it doesn't squeeze the video just cuts the view?
Once you're sure the aspect ratio is locked, click on a corner handle and drag in towards the center. You just zoomed in on your video.
Do it with key frames and it happens over time. Just set the first key frame either at normal or zoomed in, then set the last key frame either zoomed further in or out. The length (span on timeline) determines how long the zoom takes. Ditto for panning left or right or whatever.