If you don't cause her to hate you it can be slightly easier later on for the side-quest involving her, but it doesn't matter so say what you will. Choose whatever fate for those morons you wish and continue forward to meet Lashowe. Go forward and you'll meet Shardaan who is threatening various idiots with death. Our first goal here is to get in to the Sith Academy. From here on forward there are many opportunities for both dark and light side points, so make sure you check the Korriban Dialogue Page.
Like the other planets once you land here you need to pay a fee, though it is considerably less here (only 25 credits), and this can be bypassed easily enough with an easy persuade check. Since Korriban can be very difficult if you just barely left Dantooine, and since Bastila will also be unavailable for the duration, I suggest that you come here last.