You're probably over-thinking things. I've found that was the worst thing about having to wait for delivery. Too much thinking, reading, YouTube... At the end of the day it's just another camera. In spite of all the things I read during the wait as soon as I started fiddling with the camera I realized that for setting it up the way you want it's not THAT different from the high end DSLRs. I thought I'd be setting up multiple shooting/custom settings banks. Never have on any of my DSLRs. But I shoot wildlife 90 percent of the time with the remaining being landscape with the rare kids' sporting event. And I shoot fully manual with occasional auto iso. So multiple banks aren't really useful/relavent to me. OK maybe one for landscape and one for everything else. And maybe a third with subject detection set to people for the occasional ball game. OK maybe the banks ARE useful....
Here's what I've found different:
Viewfinder: loving the zero blackout EVF. There are multiple choices for what information you want to see in the VF. But the biggest decision is whether to set it up for WYSIWYG or bright. I like WYSIWYG since I shoot manual settings and occasionally get in a rush and get caught out. Typically have ss set low and then a BIF opportunity pops up.
AF: For all practical purposes for my shooting I went from two to three useful AF modes.
- DSLR: I only used AF-C with BBF. On the bodies that allowed it I disabled AF-S to avoid accidently switching and getting caught out. The only two focus point/areas that I use are single point and group. I have AF-ON set to group and F1 set to single point(usually only used on static subjects).
- Z9: Same as DSLR I only use AF-C with AF-S disabled. For my shooting the only three focus areas that are useful are: single point, wide area L, and 3d tracking. I'm testing going back to shutter button set to wide area L, AF-ON set to 3d tracking, and my traditional F1 set to single point. Jury is still out on the shutter button until I get a few hours of practice behind me. I may go back to BBF on wide area and set another button to 3d. Many years of using BBF has worked well...
AF comments: "Wide area" is an odd choice of words for that mode. The focus area isn't that "wide". And not that much difference in the size of the boxes between S and L. And with focus point persistence once AF locks on to a subject it will track outside the box until it reaches the focus tracking time limit you have set. If you get the subject back inside the box before reaching the time limit it appears to reset the timer. In theory subject detection should work faster in wide area S due to the smaller area to scan. But for practical purposes I'm not sure it makes a difference. So to simplify and since I shoot a lot of BIF I disabled wide area S as well as all three dynamic areas(never used them with DSLR so why now). Pin Point only works in AF-S so is a moot point(with AF-S disabled).
Mechanical vs Electronic shutter: Oh wait... there's not a mechanical shutter. One less decision
Though you do have to decide whether you want the protective shutter to close when you turn the camera off. OK that one may be an IQ test
Maybe if you configure it to stay open they come and take the camera back...
I'm sure plenty of people will chime in with plenty more to think about. But I'm simple minded...