I think going to the Jedi Academy was a necessity of the storyline.
But I do think that if you chose to be DS, then while on Korriban the other students should have reacted different to you. The problem I had with Korriban is that regardless of whether you remained a Jedi or went Dark side, all the remaining students wanted to fight you.
It would have been cool if the dark jedi in the game acted differently towards you if you decided to reclaim your mantle of dark lord. maybe not necessarily join your party, but something like a dialogue tree where they pledge their allegiance and let you pass by without fighting them.