I've decided to split some ideas from the contributing post into their own topic, so I can better explain them in a single contained post. This is the usefol tweaks program. I would really appreciate it if a tool like this was made. It would improve the usability of older/newer Windows versions alike.
I believe a lot of the framework has already been laid with Open Shell. I think it could be used as the basis for this tool.
Ideas:
Win + X menu like in 8+. I assume the options can easily be implemented in the application menu so right click and Win + X could work to open the start menu options menu with these options added.
Dragging and dropping to explorer breadcrumbs. This is missing from 7 and is a useful feature if you want to copy or move something a few folders up without needing to find it in the file pane.
Add My Computer folders to 7 at the top in the same sort order as 8.1.
Add Recycle Bin, Control Panel. and other icons that are in the desktop folder on 7 into 8/10.
Backport to 7 the connected to USB 3.x text for USB devices, and the this device can perform faster text if it's a USB 3 device connected to a USB 2 port.
Go up button (This is already implemented in Classic Explorer). However it would be nice to have it optionally replace the stock one in 8+ as the 8+ go up button is smaller than the back/forward buttons in 8+, where it's the same size with Classic Explorer on 7.
Active window indicator on the taskbar being the icon colored hover color rather than just the basic lighter coloring.
No duplicate USB or other devices in the file pane on 10. (Generic image as I don't have 10 on hardware to test lol)
Bring back the My Computer bar.
Backport to XP/Vista. I consider the 7 start menu almost perfect. However the earlier menus have some jank like you can't remove recent items from the Vista menu, or add downloads to it. XP also has no search bar.
Probably more when I think of it.
If backported to XP/Vista:
7+ file pane for XP/Vista. The earlier ones are weirdly jank and scroll everywhere and just are harder to use. The 7+ one behaves more naturally and is just better.
Taskbar pinning and dragging items around. I find taskbar pinning to be better than quick launch, and I like having my programs sorted in a specific order no matter how I open them. (I don't think I need an image for this)
Capacity bar for USB devices on Vista, and drives/USB devices for XP.
Optional:
Implement features of OldNewExplorer. There are some conflicts with Open Shell and OldNewExplorer like opening libraries folders from the start menu shows them under a phantom This PC folder for them instead of the library. Considering stuff is already being done with explorer, I assume this would be relatively easy to implement.
Aero Snap for XP/Vista. I assume this is a little too unrelated to what is being done here, so this is optional. I have also turned this into a request, the post of which is here.