I think the fact that roundabouts are uncommon in the USA explains any stupidity encountered on them. Usually the problem is people entering when they shouldn't, and that is a problem you encounter with all types of intersections anyway.

Also you would be wise to call them roundabouts so as not to disrespect the one we own.

Mind you, the "always able to turn right at traffic lights" thing in the US is glorious. Too often do I sit at lights waiting to turn left when there is smurfing nothing there.