I reimported a ME1 character from scratch and ended up playing LotSB the moment I hit Illium. Here are some things I noticed.
1.) I seem to be unable to complete her original pre-LotSB mission of hacking... I liked seeing her go after her secretary. But cest la vie.
2.) completing the LotSB prevents all other romances from moving past the "I like you" scene. I went that way with both Tali and Miranda, and Liara's picture was still up... why? I was happy with having continued the ME1 romance and I wanted to see how the game reacted... it didn't. When the final mission came? I got the cheerleader doing her cheerleading routine. So both romances appear to be 'silenced' and a ME1 Liara LI save that 'continue's' with Liara? is forced to be faithful for the rest of the game. Which I think is great and all, just found it interesting.
3.) When you return to Liara's Lair, the thing that is supposed to be her appears to be a V.I. and an exceedingly simple one. Even after I "return" after killing another Reaper, she stares straight ahead and says 'thank you for stopping by'. Which to me? says Liara is somewhere else other than there... and why no dialog after I finish the main storyline? I was hoping for some sort of neat scene but was only left with the damn VI hologram... and there was no option to ask Feron where Liara was...
on a side note, I still think Ashley is a liar... I have yet to play through with Kaidan left alive. but Ashley starts off saying she would have followed Shepard through hell itself... is she just stupid and doesn't know where the name Cerberus comes from? However, I never really liked her anyhow... I am beginning to think I should have saved Kaidan instead... at least his character seemed to have more loyalty to Shepard than "Alliance Brass"