When you said "I would say then that unconscious sex is just off-limits." — did you mean that pragmatically only (as a matter of being careful about law as it happens to be), or as your own position morally? (You say you don't "also" think other things I listed are off-limits.)
Re BDSM: I fully agree with what you said, but unfortunately that's still not the state of the law in some states. (It's been improving gradually.) I do think it has a great deal to show on consent in general to things that are normally clearly illegal without consent, and "consensual non-consent" as a subset of that.
> I cannot grant the premise that all seniors are senile or have dementia. There is a wealth of evidence to the contrary.
I didn't presume (and don't believe) that either, but I acknowledge that I was unclear. My question of course pertains only to those who do have the condition described.
> No, I would not say that, however I'm guessing these cases, while I'm unfamiliar with them specifically and I'm taking you on face value that they exist, are complicated by communication and pornography laws. Inconsistencies need to be addressed.
Yes, there are differences in laws about statutory rape, possession/production/dissemination/etc of pornography in general and child pornography in particular, etc — both within and between states, let alone between the states and the federal laws.
(Hell, there are still differences like cousins being legally allowed to marry in one state, and criminalized for having sex in another.)
I gave the various analogies because they all have the common element, of someone being legally unable to give consent (under current law, in some jurisdictions).