I'm suposed to go and talk to Wardeck so I can find my brother. The marker points to the Seperatist converter, but I cannot find Wardeck anywhere even when I'm standing on the yellow marker. If he isn't there, this is a game-ender of a bug. I'm hoping that he is just somewhere hidden or hard to find? Can anyone help with this?

I did this quest and found him inside the Converter. As you walk straight in, you see Sestak standing under the light on the platform. Wardeck is standing in the corner to your immediate right. He was hard to see because it's dark there.
There are a few extra Seperatists milling around and he may seem to be one of them. Check again. If he's not there, then I'm stumped. Try doing some related quests and see if he shows up.