I just fought the Sand Demon for the first time at level 29. Kira died (despite Guarding her), and I had to use one medpac, but otherwise it wasn't that difficult of a fight.
I'm pretty sure I had it happen one other time. Had the same thing happen to Aric Jorgan, the first time my trooper met him. He's all "Respect mah authoritah!" but he's tiny, so it was awesome.
I had no issues with Kira. Got her quest after Nar Shaada. Didn't pick the dark side option because I'm light side and never pick dark side options. Got a few more convos with her afterwards and kissed her.