I apologize I don't have time now to read all these replies and your responses to them, so this may not take some of that into account.
For a first bike, if you have opportunity to take it off road at all, I'd think for me starting over, a smallish dual-sport, maybe 250 - 400 cc and actually take it out in the dirt and learn to ride.
If a dual-sport doesn't work for you, maybe a Kawasaki Z-400 street bike. When I started I got a Honda S-90 and put 12K miles on it, took it everywhere except the freeway and had a blast. But if you're gonna go on the freeway, you should probably get at least 400 CC.
BTW - a Z-400 is plenty fast.
The lighter the better to a point.
If you really wanna learn to ride street well maybe get a supermoto of some sort. Supermotos are really modified dirt bikes so you can take them in light dirt too.
I do think an FZ-09 is too much to begin with. Not that it can't be done, but you'll always be frustrated that you can't gas it for more than a few seconds at a time unless you want to risk going to jail. And you really don't want to take an FZ-09 in the dirt except maybe on an occasional dirt road.
If your point in getting a motorcycle is to have fun, (as I imagine you've read before) it's a lot more fun to ride a slow bike fast than a fast bike slow. A 300 cc bike is plenty fast enough to have tons of fun on. You won't win any straight-line contests but you could get to where you could outdo plenty of guys on much bigger, faster bikes when the road starts getting curvy.
This probably isn't very helpful. But even a Grom would be a blast - but especially if it was about 250cc.