I believe that my father has Narcissistic Personality Disorder....?

what an @sshole. I dont even know what you'd do to help the situation- sounds impossible to have a reasonable conversation with him. I would probably not invite him & then hire security if you think he'll retaliate. when he throws a hissy say, " she deserves to have a beautiful day & you already told us of your intentions to cause a scene so you did this to yourself. btw, there will be security there to drag you out if you think you're going to sabotage my sisters wedding"