I agree with @NCaquatics it's best that you're doing the research and asking the questions now instead of when you have over stocked an uncycled tank with incompatible fish that are suffering.all the bases have been covered so I dont have any formal input.
Just wanna say, you asking all these questions before and doing your research before.... this will make you a good fish owner, so don't be made to feel otherwise for asking questions
I can't think of much to add either, maybe betta alternatives. Have you looked at wild betta's? I'm not massively knowledgable about them just yet, I'm still learning! If I'm not mistaken, @Crispii knows a thing or two about wild betta's don't you? Would you have any suggestions?