Change Default Sign Settings

Is there anyone there can help me changing the Sign settings?
I know it's possible to erase the Signature with "Clear saved Signature" button.

I Would like it to "Clear saved Signature" when closing Adobe reader.
Anyone know where Earlyer "Draw Signature" is storede?

And, it whould be nice if it was possible to set it up to "Draw my signature" instead of "Type my signature" be default, when selecting "Place Signature".
I have looked in Regedit, but could't locate the String.