Agriculture and then I would suggest Masonry after, not Math. Why do you want Monotheism? For the OR bonus?
I really like the fish / clam / rice city spot south, but the problem is that it's all food, and the rest of the tiles are junk. We should use that site for a potential Globe Theatre city, although I don't think drafting 1 move units might be best in a quick game.
In the short term, we should expand close to where our cities are, for max defense and better maintenance costs. I think the sheep / fish / silk spot would be a nice 5th city for us, and it's coastal so we can use Moai Statues in order to build fast ships that can go north (and explore KK) or south, and explore the southern area. I'm not sure if the southern area can help us explore another civ, though. Side note: do you know the location of the the other 2 civs? Alternatively, another strong coastal site would be 1n of the corn, which has the added bonus of 3 lake tiles that will be 3f with a lighthouse. It's also reasonably protected from KK.
After that is the gold/horse/rice spot for it's long-term production potential. Ideally, we will farm and mine as much as possible, and hopefully put a Heroic Epic in that place. Side note II: do we have a 10xp unit? That city spot is also completely landlocked, and has no useless water tiles. (4 mountains, though

.)
What do you think our medium-to-long-term plan should be? I want us to expand peacefully, but at the same time hopefully we can deny KK more of our lands or deny him the victory at all by engaging in a full-blown war. Do you have any wonders in mind that might help?