After i went evil on Khor and changed back, Evil NPC's still greeted me as evil one and i could buy from them during the neutral peroid.

That is intentional that neutral can buy from evil and good npcs. They just want your money :-)

Khor, u'r neutral, this means u have no side yet, so, they want to get you to their side! If u turn good, I believe they'll stop talking or selling to you!

Well maybe the dialogue should reflect that since they refer to me as a 'dark one' still. Maybe they should be pitching me the dark side, or not act like i didnt totally betray them and repent.