I think that, on the whole, most people can get along just fine. The average Iranian would probably be no harder to live next door to than the average, say, Texan.
Sure, they might eat different stuff, or pray to a different God, but when it comes down to it, they're generally no different than anyone else.
The trouble comes, however, when certain people decide others can't live their lives in peace, for whatever reason. Sometimes people want to impose their will because they mean well ('I'll save their eternal Soul!' or 'I'll bring them a different form of government even though they didn't ask!'), sometimes it's because they're fearful that a different way of life might threaten their own status quo, sometimes they're just greedy. Sometimes it's a combination of those things. Sometimes it's one of those things in the guise of another.
At that point, the leaders of one group use one or more of those same motivations to mobilize their group against another. Sometimes it's religious factions, sometimes governments, sometimes political groups.
Iran's been demonized, using our fears of losing liberties under Muslim law, just like the USSR was demonized using our fears of losing capitalism (and our wealth). I'd agree the people in power there are absolute whacks and I wouldn't want to live under their rule, but I fail to see why we're in any danger of doing so. That doesn't mean that, underneath all the politics and rhetoric, the average Russian dude, the average Chinese, or the average Iranian would make a bad neighbor. Just like I'm not such a bad guy, even though I had a president for 8 years who I strongly disagreed with politically.