

The only counterargument to it I can imagine is that in shit-backwards healthcare systems like US one, it will disincentivize bad doctors from saving your life. If you’re poor and your family can’t afford good lawyer, they don’t have a good reason to give 100% to save your life, when they can give it 80%, and then sell your organs for good profit.
It’s not an argument against compulsive organ donation, more of a one against shit healthcare systems, but still.
Nope, not even close. It’s not even the basis of Christianity, and we associate that one with this message the most (for some reasons). If there is a basis that all religions share, it’s that unwavering notion that the religion in question is the right one, and every other is heresy and should be eliminated.