You really should have been able to take control of the Sith Academy on Korriban in KOTOR 1. It wouldn't have affected the storyline much, just instead of having to kill all the sith after beating the current head of the academy, you could talk to the students and they'd talk to you as if you were the head of the academy.
I mean, the explanation for that part is stupid. I'm darkside, I kill the head of the academy, come back and tell the students that. The 3 of them decide THEY want to be head of the academy, I kill them. Then the ENTIRE academy wants to challenge me? I just killed the most powerful people in the school, they should be bowing to me and begging for mercy.