Then you should have no issue with criminalizing marital rape - it can't be proved anyway, right? The fact that it is difficult to prove is actually a point for, not against criminalizing it. I already explained earlier on the thread, that since proving marital rape is difficult, proving a false accusation of marital rape is even more difficult, and hence such a law is unlikely to be misused to frame an innocent husband.
Besides, there are many crimes that are difficult to prove - that doesn't mean that those crimes should be legalized. Young girls often endure harassment that is difficult to prove - like obscence comments or gestures. Many young girls (and boys) face sexual harassment even within their family - a relative groping her breasts is near impossible to prove in a court of law. Such acts are also not recorded on cameras. But that doesn't mean they should be legalized.
Long story short, if it is difficult to prove something, then there is no harm in having a law against it, if it is a criminal act.
It cannot be proved, but could be used as a weapon to settle scores in petty marital discord.
And it is not the case of difficult to prove,it is impossible to establish presence or absence of consent ,at both material and philosophical level, when two people are in long term sexual relationship.
This has been the core of logic behind not criminalizing marital sex, which is amply demonstrated by fact that India treats "Rape in marriage that occurred after filing for separation (not Divorced; couples are technically married)" as rape.
And no, just because marital rape is difficult to prove under normal "guilty until innocent" paradigm, it does not mean that it would be misused less. Experience from West has shown that close to all cases of marital rape are fake, and are filed to force favorable divorce settlement. In India too, this would become an epidemic and a tool to settle petty domestic grievance. That is what people mean when they give argument of destruction of marriage. Giving tool of marital rape to women means that petty domestic disputes would be dragged in court and would poison institution of marriage. Apart from that marital rape does not carry any stigma, and lack of perjury laws in India means that there would be no adverse fallout for women that accused her husband.
When you presents an argument that marital rape should be criminalized, even in face of the fact that there is practically no chance of establishing innocence or guilt, thus turning it into exclusively an harassment tool, you are condoning its misuse.
Should marital rape be criminalized? Sure, when we develop a "truth serum".
Edit: For the list of crimes you have posted, no judge would condemn an accused in absence of either video-graphic, eyewitness, or medical proof.