Not sure, I have never tried moving the instruction pointer after Edit & Continue.
Moving the instruction pointer backwards has been fine in my experience if you choose a suitable line to reset your state.
> Do you get the ability to move the execution point back to before the the error, in order to resume execution?
You can in Visual Studio 2012 and in Visual 2015 some corner cases were fixed.
Just drag the arrow backwards with the mouse.
Do you get the ability to move the execution point back to before the the error, in order to resume execution? - from what I can tell, this isn't possible - from https://msdn.microsoft.com/library/y740d9d3.aspx#BKMK_Set_th...
"Setting the next statement causes the program counter to jump directly to the new location. Use this command with caution:"
"If you move the execution point backwards, intervening instructions are not undone. "