I am highlighting the following part from the question, which I found to be crucial.
Also, according to scripture, each and every enjoyment presupposes punya and at the time of rape, if one gets pleasure it must be due to his previously accumulated punya. Without punya, he cannot really enjoy the act. So is he really committing a sin and gaining new papa ...
What can a king do to prevent Rudra from destroying his kingdom and
By offering the Ashvamedha.
After the sacrificial horse has been slain in the year-long Ashvamedha ritual performed by the king, the king offers three libations of blood of the horse to Rudra to appease him so he doesn't harm the cattle and citizens of the king's country.
By supposing what an invading king would do in the same situation, we may get an answer on what the gods should do.
The Kātyāyana Smṛti on Vyavahāra (Law and Procedure), says:
Even when the king is at fault, (the conqueror) should not ruin the country (for the vanquished king's faults) since he (the vanquished king) does not start on (his career of)...
No, God does not punish entire countries for their sins.
The theory of karma only applies to individuals. God remains detached from the universe. It is primordial nature that runs the universe. Please check Gita verses given below. Gita's teaching overrides anything in other scriptures since Gita is the king of smritis.
Resorting to Prakrti, Nature, ...
This objection is actually brought up in the discourse between King Aila and Rishi Kashyap.
'If chastisement touches all viz., the honest and the wicked alike, in
consequence of the sins perpetrated by the sinful, why should men, in
that case, do acts that are good? Indeed, why should they not perform
And Kashyapa responds,...