This idea of 'offensiveness' is really what I'd like to understand. Is arrogance subjective, or at least dependent on how it is directed toward present company? Alternatively, is it merely confidence out of proportion with knowledge/experience without being directed at any/all?

I've come across both and only the first type is annoying. The second can first be mistaken as the first but then get to know them as being very enthusiastic and inexperienced (not knowing what they don't know).