zoning maps

When you're settling cities that get to close to your neighbours they get upset. How about indicating that zone when you approach it with a settler. It could serve as an expansion of the "this is a good location to settle your city" feature or as a "map options menu" item.

I'd just like to know how close is settling too close...?

In my games, whenever I straddle another civ's axis of advance, they get upset no matter how nice I am to them.

I've got the same thing. Also the don't settle near us agreements should be mutual when proposed by any party. Why would anyone follow that if the other party is allowed not to do so (which happens way to often).