The easiest solution I found for this was to use Rush and Premiere Pro together since you can open your project in Premiere Pro when it finished in Rush.
Zooming an image over a few seconds is very easy to accomplish in Premiere Pro. After my project is complete I open it in Premiere Pro and add the zoom effect there. I'm not a video editor and this is the easiest method I've found so far.
You can find a lot of tutorials on Youtube which explains how to zoom an image over a period of a few seconds.