Is pussy spanking supposed to be very light pats ?
 

I never knew if I was doing it right, I felt it was wrong because I could never properly hit like I would with ass or such. But in the few videos where I saw it performed, they were also barely hitting, more just patting ? I can't find any good reference that answers my question for good.

When you tell someone to do it, what kind of force is expected to be used ?

Hugely depends on the context: If durin play and only with the hand mostly just patting. Only sendign a little sting through the body but no strong lasting pain.

If it is clearly a pain task or a punsihment and uses a tool it should actually hurt and be stronger hits but in comparison to a butt-spankign still weaker.

It depends on the effect you want to apply, soft hits are usually done to make the zone more sensitive for stimulation while harder ones are to inflict pain.

Its about what you want to make out of it so changes each time you send it to someone.