I really struggle with this too, in fact it's probably one of the biggest autism-related problems I have. I was trying to put it into words for a blog post the other day, then came on here and read your post, and you managed to put it into better words than I had managed!
The problem is, I have no idea what is acceptable and what isn't. And if I have a difference with someone, eg. my husband, obviously we each think we are right or we wouldn't be disagreeing, but I have no idea whether I am being reasonable or not, whether the difference is because I'm a woman, or I'm autistic, or we're just two people with different opinions. And even if I can work that out (ok, it's an autistic thing) I have no idea whether that affects the situation anyway - does it mean my opinion or wish or need is any more or less valid?
As everyone else has said, the answer is different in every situation, which is why it's so chaotic and troublesome: there is no formula to follow. I know I have some idiosyncrasies that I think are just common sense, and often people try to accommodate them, but I really hate putting people out, but then again, some of them are things that really bother me.
So really, I've just vented for a bit and not really said anything, particularly not anything useful, but no, you're definitely not alone in having this problem identifying what is reasonable and what isn't