Hmm, I just read that thread, and it doesn't look good. However, for what it's worth, CDZ seem unlikely to backstab us before any treaty we have expires, as that was what started the whole mess in the first place. What does worry me though, is the attack that will come ~3 turns after.
What I would do as CDZ, if I was fully intent on attacking us, would be to have a fleet parked up behind our island, hidden in the fog. Thus, when the treaty runs out, instant army. If the world fully wraps (not sure about this) then it is even worse, because we won't see it coming.
I'm not sure how we can sound them out, because the question we are basically trying to ask is "Are you going to attack us as soon as our treaty expires?", which is not an easy one to ask subtly.
So my thoughts would be to prepare for the fact that they will attack us, and pretty soon after our treaty lapses.
By the way, does anyone know when that will be?
Another thought, we should DEFFINATELY try for circumnavigation bonus, so we can counter the CDZ UB. If they get it, their fleets will probably rule the seas.