Just saw the promo. The Narn woman is Caitlin Brown (Na'Toth). What is in the promo is taken almost entirely from the first two episodes, with just a smidge from #3. Which may give you some indication of how much action is *in* the first couple episodes (and in many epiosodes thereafter) -- definitely keeping the thing moving.
I'd say that n'grath would count as a non-humanoid alien, yes? (Just keeping an eye on my promises here....)