PSK Spot of enforcement?

[BoBo]

Question was raised on the way to the game and would like opinions please or actually the correct ruling!

Play

Scrimmage kick situation:

4th and 8 from K's 45

K punts the ball to R. K's punt rolls into the endzone(touchback obviously if no foul)
But:
1) R1 calls for a fair catch and blocks K1 at Rs 15 yard line before the ball crosses the goal line.
Where is the basic spot of the foul for illegal block on R1?

2) R1 DOES not call for a fair catch and holds K2 at R's 15 yard line before the ball crosses the goal line.
Where is the basic spot of the foul for holding on R1?

Question is with the new PSK rule since the foul occured in front of the spot where the kick ended the foul should be penalized from the end of the kick. Here the kick ends when it crosses the goal line for a touch back. So do you mark from the R's 20? I felt you should penalize the R team where it hurts them the worse. If that is not the case you can get a pretty good cheap shot in and not get hurt real bad.

What does everybody think??