I'm going to force my pizza delivery person to walk up four flights of stairs to deliver my food by threatening giving a bad tip.
What if they refuse to walk up the four flights?
Then I'm going to refuse to tip them.
Pizze delivery drivers are required to come to your door so it is unnecessary to threaten them with a poor tip. They will just resent you and not deliver to you anymore.
That's fine, I can afford not getting my food.
Since they'll deliver to your door in the first place, it is rude and unnecessary to be threatening towards the delivery person. Making them feel bad will only result in you being in an annoying situation in the future. Perhaps just let it go and tip them well.