Good suggestions.
In terms of diplomacy, there is nothing new to unlock, per se. Nothing new in the interface, although there are pieces of content that need to unlock (those are the international abilities I mentioned). Basically you can do good or bad things to your neighbors using the abilities, and they react to that. They will do good or bad things to you as well. Somewhat "implicit diplomacy," although words are exchanged. There are a few bits that are more explicit later on, but mostly it's a matter of choosing how to interact with them, and things flowing from there.
Please don't get the wrong idea, though: a lot of the things that are abilities really are diplomatic options in disguise (though they aren't implemented yet). So things like a mutual exploration treaty would be handled via these abilities. It will make more sense when you see it, I think -- overall it's pretty straightforward and gives you a really centralized way of looking at your diplomacy with all races, which I'm pleased about.
Amd om terms of buildings that AI neighbors react to, that is also definitely something that is coming. The local events I've been discussing are exactly that, although we've implemented the framework but basically no events. That's on my very short-term list.
