For 0 and Kiwami screen tearing is only found in a couple of points on the map (Theatre Square is the one that springs to mind), and that's mainly if your quickly running and moving the camera all over the place. If your moving slower your far less likely to see any. Pretty much other area should be ok, back when I did my base PS4 playthrough I only remember seeing consistent problems in that one area, and that's only for a brief moment.
Boost mode via the PS4 Pro completely eliminates screen tearing though, really glad my second playthrough on the game was on my Pro!
Sounds about right. Bare in mind the more fans you get in an area = better paying customers, so its worth getting a fair few fans before doing the club battle challenges to ensure victory. Also as you tackle later areas you'll get more money, but you'll never make close to what Kiryu can make via Real Estate. But you unlock a side story at one point where you'll be able to transfer money from one character to the other, which makes it easier to get Majima levelled up.