HC: Because a large penis isn't always evident in a public situation (myself included, as I'm just about average or below when flaccid and don't show much of a bulge), it's not a factor for intimidation when meeting a woman. And if they happen to experience it first-hand in a private setting, they might be scared if it appears too big for them to accomodate, but I wouldn't think it intimidates them per-se, as they've already gotten you into bed and there's no competition with others for you at the moment.
On the other hand, if a female has large breasts, it's quite easy to tell, unless she's draped in a potato sack. Being one of those nice guys, seeing a "stacked" woman in a bar does tend to intimidate me on occasion; I will think "she's too widely desired for myself to stand a chance."
As for a woman being offended at the notion of a big dick or a bumper sticker advertising it, I'd tend to think she's most likely the devout religious type who is easily offended at most things.