Yes, I'd agree with that. At some level, all things are human constructs and these change with time. My point is more that we are free to make our own constructs and it's quite hard to make others accept them. If there are no absolute truths (scientific facts) then it is perfectly feasible to...
I agree with most of what you say, but this is a fallacy. We are all people and our minds don't have absolute reference points. We feel as we do, we have no idea what a "man" or a "woman" feels like to determine our feelings-based identity. There are many people who feel they are in the "wrong"...