Andrew,

           I know nothing about moviepy or ffmpeg, specifically.  The observations I've made are general truisms.

           Very often I've seen people set up plain text files with "skeleton commands" where they copy and paste those over and over and over again, tweaking the bits that need to be tweaked.  If you do a lot of scripting, and repetitive scripting, no matter how you automate or semi-automate the process you're definitely not going to want to be typing everything out by hand every time.  You'll likely have to edit the template material after pasting it in, but once you're familiar with the various commands, their arguments, etc., that's quite easy.  It's the learning curve for any new piece of software, whether accessed via the command line or GUI, that's the hard part.
--

Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042  

The depths of denial one can be pushed to by outside forces of disapproval can make you not even recognize yourself to yourself.

       ~ Brian Vogel