It will be added there at some point. At the very latest, when Reforged is released.
I’m not entirely sure, what you mean, but fullscreen is supported and also widescreen is also now supported, so the graphics aren’t stretched anymore. Ultra-wide screen support is also likely coming at some point. To unlock >60 FPS you still have to put the “-nativefullscr” on the Warcraft III.exe shortcut, but I’d imagine this will be fixed too at some point.
That is correct.
Basically, the largest changes are totally remade graphics and revamped campaign. Also much of the coding and “under the hood” stuff is getting updated, so it runs more smoothly and you don’t need to mess around with other files to get it working most optimally (like porting for hosting, fixing shortcuts to remove FPS limits, and so on). Many of these changes will also update the Classic version though.
For a more proper list, check: [Compilation] ALL we know so far!