Pivot Ftilt is good against Fox Dair but sometimes you can just Ftilt him right out of the Dair without any need to whiff punish. Trading is in your favour as long as Fox gets knocked over (14% or above for up-angled Ftilt).
Pivot Dtilt is really hard but if you can do it, it would have uses as a whiff punish. Slightly slower than Ftilt though, so you might find they can shield the Dtilt (which is still safe if you space it, but imo getting the hit with Ftilt would be better).
Given the poor horizontal range of Utilt, I think it would be very hard to punish anything with it. If you retreated out of the way of your opponent's attack, they're already outside the range of your Utilt. Pivot Utilt is also extremely hard to do.
Pivot Fair and Bair are both good for getting the max retreating or approaching distance. Being able to threaten pivot Bair and run cancel Dtilt out of the same dash forward is great.
Crossup Pivot Dsmash is good if you are cornered and get a jab reset. It lets you Dsmash them off the close end of the stage instead of doing something like cross up Nair.
Pivot parry is the impossible tech no one asked for and no one would notice if you did it anyway. But you'd probably feel pretty cool if you did it.