Is there a way to play music in real time while simultaneously watching a video. I’m using Sampliude ProX5 Suite. I am scoring a video and would prefer to write in real-time.

You can import (or drag and drop) a video into a Samplitude project. You can also open a video window (I think in the menu "view") where you can see the video while listening to or recording a project.

Of course, in this case your computer has to work much more and a proper graphic card is very helpful.