Ghostbusters only needs one more sequel. But if they wanted to do a spin-off with Podcast, like I said before, I'd be happy lol
There's not too many characters when you're dealing with a "team" based movie like this. If the character screen time is balanced, it's a non-issue.
This moving making money is because it was genuinely good. Nothing to do with the "movies being back" (trust me, even with the most popular money making movies, the theaters are still barely getting by. Hence the surge of movie swag to entice people). Sure having original cast back will get people to go see it, but there are surprisingly a lot of people who have yet to see "Afterlife" (and I judge them harshly lol).