It's no zooming in zoom in the preview but I have not tried it after rendering the movie. I had seen in prior posts that if it doesn't zoom smooth in preview it may not after rendering but not sure.

As I'm sure 3Point is suspecting, it could be that the preview is lagging even though the final output will look fine.

You can smooth out some of the playback by reducing the playback quality on your Preview window. It may look blurry and low-rez, but at least you'll see the panning and zooming more smoothly. And, of course, this preview has nothing to do with how it will look in your final output.

Thanks Steve...I was just watching your awesome tutorials as I saw your reply. Another question I have is that I am combining many different cell phone videos with the typical cell phone vertical frames (black boxes on sides) and different aspect ratios. When I render the movie can I make it so the whole movie has the same aspect ratio and it fits a full youtube screen?

 can I make it so the whole movie has the same aspect ratio and it fits a full youtube screen?

To do this, you can use pan/crop to zoom in to make the vertical phone image 16:9. but the quality loss will be huge especially if the recordings are in less than 4K.

I seriously do not understand why people use their phones to record video in the vertical. Surely it's not all that hard to hold the phone in the horizontal position so as to record in 16:9 with maximum resolution if the intended destination for the video is TV or YT. Think of it this way - in HD the horizontal image is 1920/1080, but if the phone is held vertically, the vertical image is 1920 thus making the horizontal image roughly 1079. That would make the vertical roughly 606 if the HD vertical image is zoomed in to 16:9 on an NLE like Vegas Pro. That's almost analogue quality from decades ago. Of course, those figures would be doubled if the recording was in 4K - but it's still a huge loss.