"You won't find real atheists expressing certainties."

There seem to be a fair number of unreal atheists in that case.

I couldn't agree more. To be fair, a lot of people who, rightly, utterly reject God do so with the same certainty as the religion that riled them in the first place preached God to them. I don't for one minute deny that certainty-atheists are really atheists, but they have yet to articulate their atheistic arguments fully. A bit of thought tells you that you can never prove God doesn't exist. The odds against his existence are absolutely huge, of course, but there will never be definitive proof.   

As for "I have to look at religious iconography wherever I go" I'd be inclined to say that all of us are exposed to a far greater amount of materialist and implicitly anti-religious (and for that matter anti-humanist) imagery everywhere we look. Papers, TV. advertising...

True again, but you are not comparing like with like. Religion is a completely human construct, and there's nothing more most of its adherents like than to impose it on the rest of us willy-nilly. There's even a current thread here "asking for prayers." If I'm on this very secular board and I have to read that rubbish I could well feel quite insulted as an atheist, but I'd far sooner ridicule it for what it is, or just ignore it. It's very rude, isn't it, but it happens all the time, and we accommodating pagans just fart in its general direction. The stuff you refer to is entirely reactive. But for religion it would not exist. To criticise it is to suggest that religion should get a free ride. Heaven forfend. I could suggest to you that the whole of nature, in its glorious ordinariness, is the ultimate anti-religious testament, and it certainly far outweighs all that stuff you're moaning about, if only all those blinded believers could see it.