1. Showing the target's model alongside the focus target indicator would be too distracting.
2. Grid snapping exists already, but the adjustment speed on the HUD layout is janky slow (at least for console players).
3. I'm pretty sure you can copy and paste hotbars on the PC version, it just requires rooting around in the game files to do, so it's best to keep plenty of backups so you can restore if it goes awry.
4. There are vertical hotbars already, you just can't map the cross hotbar to be vertical at this point in time.
5. They've implemented the feature of having Eorzea time and Local/Server time together, it's in Character Customization.
6 & 7. Valid suggestions.
8. Classes in this game share rings based on Str, Vit, Dex, Int and Mind for the combat classes, and DoL and DoH all share their respective attributes too. If you're lacking ring box space, level your classes equally so the equipment isn't crowding your ring box, unless you're cramming glamour items in there for which case you'll have to put up with it.
9 & 10. Valid suggestions.
11. If they're going to add notifications to show when people come online outside of your FC, it should go in the following heirarchy: Friend > FC member > LS member. No need to be getting three (or more) notifications when your friend who is in your Free Company and your private linkshell logs on for the day.