I killed Patches on my first playthrough, too.
I thought long and hard about it the second time, too -- I never bought anything from him; so I should have. Killed him, I mean not bought something
The worst part is he gouges something awful on his prices.
I killed Astraea the first time as well, but let her kill herself when I found out you didn't have to kill her.
I thought Scirvir would be cool from his load screen illustration. He looks like a brave, noble, warrior. But, he turns out to be a stuttering little girl.
Biorr is awesome. He makes the penetrator fight a breeze. And he's completely insane and sounds drunk to boot!
Yuria's my favorite; I love the duality... cute, sweet and shy, yet deals it dark, deathly magic. "Yes, Yuria I am sure I want learn how to kill instantly with the wave of a little stick!"