I say yes, finalize the script first then concentrate on the other stuff.

If your doing this thing alone then you better accept that you are in for a ton and a half of work ahead of you. but that being said, If you are persistent and keep at it, you are going to finish before you know it.

I am currently doing my own Short as well. I am a beginner but I do have a sense of direction.
I will check in from time to time to assist you, and do my best to give you good advice.

**I have always wanted to learn how to render in layers properly. Where did you learn it?