I actually just got Yakuza 0 yesterday, first game I've played in the series.
You're in for a very good time. There's no other game like it.
And the story in 0 is phenomenal. Just starts off a bit slow the first few hours.
Majima was the crazyest and funniest part of Kiwami, I have encountered all of it and it was always epic and funny. I missed him on 6. So I'm sure I'll love some Majima on 0.
Small open world make it more enjoyable for me.
Yeah, Majima is always good times. Though given your knowledge of him from other games, you'll still be quite positively surprised by Majima's part in this one. I won't say more than that, but you'll soon realize what I mean.