When I don't really know someone, for example met few times only, I can never say whether this person likes me or not. Also, I don't ask myself this question*, it's premature. To me, to like someone is to know someone, this requires interactions on many levels. As of feeling, nearly always (still when I don't really know well someone, or only met few times) I do not feel not liked. This is probably because I'm open and have friendly attitude towards everybody. Go back to (*).

I usually get the feeling when someone is uncomfortable around me and nearly always try to put someone like that at ease. Again, this doesn't mean someone doesn't like me or that I don't like that person. It means that for some reason this person is uncomfortable. This can have nothing to do with me personally. Go back to (*).

This is not always true and can be faked (otherwise we wouldn't have possibility to enjoy cinematography), that's why all communication matters.

Most times I'm uncomfortable with passive aggression of that kind. Sarcasm is something else and in low doses served with humour is acceptable and even funny.