I struggled for hours trying to find information on the second point: Use Shell ContextMenu in Your Applications. There are tons of discussion on how to code a Shell Extensions and add it to the context menu of Explorer.exe.
So, where can I find informations on both those different stuffs?
Most common Tag: [windows-shell-extension-menu], [contextmenu], [explorer], [shell-extension]
Use Shell ContextMenu in Your Applications
How to show Windows Explorer context (right click) menu?
External example from codeproject.com
Coding a Shell Extensions for the context menu of Windows Explorer.exe
External example from codeproject.com