Draven vs McLeod: Highlander/The Crow

[Sire Of Dragons]

Now I know I missed a few things in these shows and movies over the years ...

I wonder these questions:

What happens to an Immortal when any other body part is cut off?
Does it grow back?
Or what if he or she is cut in half...

And :

What happens if The Crow get his head cut off?
Does he cease to exist or is he somehow remade?

Opinions and theories welcome!

 

[Sire Of Dragons]

Do we need to involve the Jedi in this?