Actually, I took Tolgeiras up on his offer to slay Valygar. Then I met Valygar who changed my mind, even though I'm LN (hey, this *is* RP after all), and I returned and told Tolgeiras to pound sand. He said "I'll get you for this" etc. etc.
I had to kill Tolgeiras and a buddy on my way to reactivate the Sphere and make the last jump in fact.
So, did I just choose the wrong dialogue??? I buzzed through pretty fast.