If I draw my Critical Miss card, can I apply its effect so as to mitigate it?
I've possibly already answered this in a roundabout way here.

The short answer is none of your options.  The attack did no damage.

There is no such thing as a "miss" or "critical miss" card in Gloomhaven. The word 'miss' does not appear anywhere in the rules.  It is a 'null' card.  

from page 11 of rules


  A “Null” symbol means that no damage is done by the attack.


If you pull rolling modifiers and then draw the null card you did no damage.  If the base value of the attack and any other rolling modifiers do not come into play. 

Its important to make the distinction between damage and effects.  if you attack added poison or you pulled a rolling wound these are still applied as these are not damage and the attack didn't miss as there is no such thing.