I just thought I'd post an update since I was finally able to get a working GPG key created, just now. I did it by using Kleopatra instead of GPA. I feel like it's pretty non-intuitive to be forced to use Kleopatra instead of GPA because GPA keeps crashing. I'm going to leave this one open for a while in case someone has a solution / workaround for creating keys with GPA instead of Kleopatra, as I'd be quite curious to hear it.
This feels like a bug to me that you can't create GPG keys in GPA without it crashing, and have to instead create certificates with Kleopatra. Mostly, I just wanted to update this in case anyone else is having this same problem, so that they'll be able to see how I solved it.