strat.res./riverside graslands
From the riverside-graslands in the BFC CERN-6 is the only possibility for an early hiden resource. I don't like the idea of mining or pasturing our first cottage after already working it for a dozen of turns. So I recommand improving the other possible riverside-graslands first (as long as it doesn't restrict our workers or economy).
-> chop CERN-9 and/or CERN-6-6 and improve these tiles (before CERN-6)
farm vs. cottage
Thinking of (fast) further growth (when not chopping 2nd settler), it would be best to work clams+rice+X then.
X could be a grasland farm (has still to be riverside) or a riverside grasland cottage.
I think it would be a good choice to go with the cottage as it will delay growth just very little (or maybe not at all; haven't checked stored food, production etc.). Further a 3 commerce tile (cottage) would be an +23% commerce/research increase.
roads
Concerning roads I would wait 2 or 3 turns until Ana. has revealed the 3 tiles in the east closest to CERN.
I think after these 3 tiles we can most probably say, where we want to settle. (Still 2nd rice looks most appealing to me or else a city in our western backyard.) (I think these 3 tiles will most certainly determine how we grab the gems and the 2nd rice.)
When we know, where we want to settle first, we can find the most useful road-route rather fast.