Merging here requests for having ctrl and shift keys change the drop action.

• Ctrl+Drag should copy the file
• Shift+Drag should move the file (in situations where copy is the default)
• Alt+Drag should create a shortcut to the file in the new location

For future reference: we can check the modifiers to see if the right button is pressed.

if (e.Modifiers == DragDropModifiers.RightButton)

Right click drag to context menu on release is critical

This is a can't-live-without feature for many.

While it is true that many are unaware of this function in explorer, most people find it quite useful once shown.

Right click drag to context allows moving/copying/duplicating/extracting/creating shortcuts and more (because other apps can add entries to the context menu), all purely with mouse, with a single hand. It is also generally much quicker than clicking on toolbar buttons (which generally won't exist for the full range of possible context menu functions).

Most of these operations can be done with key commands, purely on the keyboard, with a single hand. However it is still very good to have the pure mouse option as well. This is an important accessibility feature.

Personally, I've been right click drag context menu-ing to extract archives to auto-created auto-named directories via 7zip/WinRAR context menu entries for about 30 years now... so that's really not easy to let go of.

I know many people like Ctrl/Shift/Alt drag for copying/moving/creating shortcuts -- however it is worth recognizing that that requires two hands with two devices, which makes it less than ideal for many people and in many situations. That also does not account for the full range of operations that right click drag to context provides.

Of course copy/paste/duplicate can also be handled just through the context menu, without the dragging, using only mouse. That does not account for the full range of operations that right click drag to context provides either (without additional interactions -- like creating a shortcut, then cutting, then pasting).