I think Professor Diablo's point is well taken on the rules language.
Let me offer a possible "rationale" for the rule tweaks, following up on TxMike's statement of PSK philosophy: "Is Team A able to deliver on its intention to give up possession, free of a B foul?"
If B fouls prior to the kick beginning, then no PSK...it is presumed that the B foul may have affected A's execution of the kick, so normal enforcement is used.
However, if B fouls after A has delivered foot to ball (plus the other conditions), then the opposite is presumed... B's foul did not interfere with A's intention to give up possession, so B will get the benefit of that possession but still suffer from the yardage penalty for its foul.
If this rationale is sound, then RRK/RNK would be PSK fouls if the other conditions were met... A got the kick off "clean" and the foul occurred thereafter, so B gets the benefit of possession plus penalty.
(Personally, I don't love this result, given the danger to kickers...ought to be an Uberpenalty, like RPS)
Just a thought....