> "The foremost cause of sexism is the fact that many males (consciously or subconsciously) perceive women as mentally and physically weaker"
If this is true, it is not a proximal cause and amounts to armchair psychology. Like I said, sexism today is generally institutional rather than individual. Since you may or may not be familiar with what that means, I will clarify: social institutions are the things in society which you as a member take for granted as aspects of social order, of norms of behaviour, of the sorts of social relationships which you may form with other people. (I like to think of them as: memes which organize societies.)
So for example, you are maybe technically correct that sexual harassment is not one and the same as sexism: however, a workplace that allows sexual harassment is a sexist institution, and to complain about widespread sexual harassment is to complain about sexism as a whole.
Like I said in the post you are replying to, you are trying to view sexism as an individual's act. But if you look at the way that sexual prejudice and sexual discrimination actually emerge you'll see that it happens because women and men have different role models, different social organizations, different education models, different standards of behaviour, and different norms about what sort of conduct is excusable or inexcusable towards us.
Let us return back to the case at hand: a woman has to fend off many requests for sexual favors and many absurd abuses (like licking her tattoo -- do you really think that this person also licks men's tattoos?) simply by virtue of being a lady at this conference. You may object that the individual requests are not sexism per se, they do not promise any special treatment to a woman if she accepts or any inconvenience to a woman if she declines. What you're missing is that taken as a whole the atmosphere generated by these requests does amount to a special treatment and an inconvenience, and therefore as a whole this is sexism.
In this respect you have been missing the forest for the trees.