I think they said back during E3 that yes, most of the dialogue choices were cut down for the purposes of the demo. In fact I think the E3 demo had more options, including one with the Krogan female. You may have noticed that her and Shepard's dialogue automatically varies slightly depending on your previous choices.
It might also be worth remembering that in ME2, it's not until you run into Jacob that you have anything close to a real conversation. All the bits with Liara/Ash/Kaiden and Joker are the same basic paragon/renegade binary choices. Either way, I wouldn't worry.
P.S. I just got me a Krogan soldier class!