Ah, I wasn't very clear. I wasn't rendering very big at all. In Keyshot I was rendering an AVI at 1920 x 3837, but when Photoshop was making the mp4, it wouldn't allow that size. Apparently it would only allow 2304 to be the largest amount of pixels in one field when starting the project. So, not knowing that, it was resizing and creating those bars. Now, I simply change the size before I hit 'render', and the turntable comes out great.
Also, since I've made my CPU to 100%, and use 'Denoise', my render time has been reduced by 60%. And oddly, in the 4 new renders I've done this way, not one has given me that 'SET UP' never-ending progress bar issue.