Hi, atthecshore,
If it is a widescreen image, then no way to avoid the zoom with Ken Burns. Unless you zoomed it, the start and end points would be the same, imparting no motion. If you could crop your photo in the media browser (not the timeline) so that it is something like a vertical iPhone photo, then you could use Ken Burns. You would need to set the start point into the black area, outside the parameters of the photo so that you could set your start point to the left, and do the same thing with your end point to the right.

Alternatively, you could overlay your original photo onto a black background, and use the Picture in Picture feature with keyframes to animate the photo and make it move across the screen. Here's a link to a help tutorial that explains how to ues key frames to animate a picture in the PiP feature:
https://help.apple.com/imovie/mac/10.1/#/mova1aaa682b
-- Rich