First of all, what do you mean with "kappa-study"? Do you refer to the Measurement System Analysis Study (PPAP item 8) or to the Initial Process Study (PPAP item 11).
I don't know which PPAP Manuals some of you are reading, but both items need to be fullfilled to get full PPAP approval. A Gage R is mandatory for attributive measuring equipment, Gage R&R is required for variable measurement equipment. As far as sample selection goes for the MSA, you should randomly take a number of parts from your production line, no proper selection need to be done apart from ensuring they are OK-parts. The study will show if the variation is to be found in your products or in your operators.
Without proper GR&R, you cannot do a proper Initial process study anyways.
As far as the initial process study goes, this needs to be completed for all significant characteristics that have been identified on your product/process. If you do not have any SC's , than i would wonder if a proper component review was conducted.
If we are talking initial process study, there should also be no "sample selection". The standard requirement is that you collect a significant amount of OK-parts (>50) from your R@R and use these to conduct the the capability study.
So basically, yes, according to PPAP 4th edition, both items need to be fullfilled.
Hope this helps,
Dominique