I think one of the things SNW has been trying to do (mostly successfully, imo) to make it feel like old Star Trek is have all the episodes be mostly self-contained, but that does mean that when you do have a through line it can end up feeling weirdly disjointed; it was true of the plot with M'Benga's daughter in S1 too, even though I enjoyed that one better.

I think whether you see chemistry between actors can be subjective, but a perceived lack of chemistry can ruin even a well written romance, which this one isn't.

Ha, Ortegas was who came to mind when I was talking about characters who had more chemistry with Christine than Spock does.