I'm currently working at Experimax in Coon Rapids, Minnesota, as an Apple Certified Macintosh and Apple Certified iOS Technician! If you have any Apple related questions, feel free to mention me @jonaharagon in the answers forum and I can take a look!
I don’t only do Apple stuff though! I hold a CompTIA A+ certification as well, and have extensive knowledge of Windows software and Linux system administration.
Website: www.jonaharagon.com
Email: jonah@triplebit.net
LinkedIn: https://www.linkedin.com/in/jonaharagon/
You don’t need to patch the installer for a 2012, the 2012 MacBook Pro supports Mojave natively and will support Catalina this fall.
8 GB drives should work fine, I wouldn’t go smaller than that. I believe it’s around 5-6 GB total used for the installer files.