2) I once saw the AI do it to me: he signed OB, sent a Galley to inspect my cities, saw they were weakly defended (hey, I was on a continent alone) and attacked. By OB we let Zara see how weak we are now. (and we are weak, in the Power graphs of S-GOTM we are on the bottom)
True, this very scenario could happen, but with a Galley being replaced by a Scout.
However, consider that we have no plans to build an Axeman. The longer that we delay Opening Borders, if we plan to open them soon anyway, the worse off we'll be against other SGOTM teams who do get Trade Routes for their Cities.
Also, I would like to think that AIs are not totally stupid in their algorithms: other than Montezuma or other "crazies" like him, I do not foresee see an AI that has 1/3rd the number of Cities attacking us. The relative City ratio plays a big role in how they evaluate the Diplo situation and whether they will attack.
Our Power level is low relative to other SGOTM teams' Power levels, but I would imagine that Our Zara's Power level is also similarly relatively low compared to other SGOTM teams' Zara's Power level. Try saying that sentence outloud without getting confused!
I looked at our Demographics. In the early game, Zara had 3 to 4 times our Power level. Now, he has about 1.65 times our Power level. I'm not sure how The Oracle, Writing, Code of Laws, an extra Religion, and an extra Missionary will calculate into that value, but we'll (if all goes according to plan) have those things in hand by the time that we can Open Borders with Zara.
Finally, I will come back to my argument that I'd love it if Zara attaked us. Why bother to throw Hammers in Riverside into Cultural buildings if we can just throw some Axes to take back Riverside (I'm assuming that we'll lose the City in a war) and Zara's capitol, leaving him with some meagre City (we'll wait for him to settle such a City, if he hasn't by the time that he declares war on us, before robbing him of his capitol).
We also would remove the need to trade for either Cow or Clam--we'd have them all!
The sooner that we get into a War, the sooner that we can have a Great General for either:
a) One less Great Person needed at the end of the game
b) A better military-upgraded once we have the required techs to pump out a solid attacking force