So here's the general information about the character cohort that I have created.
The cohort, named Rat Fawkes, is a Rogue under the subclass "Bomber" at the level of 8 since my main character is actually level 10. With items and various feats, he's designed to be unhittable and very annoying. My DM allowed any feats and books to be used as long as they were published in some form or another, with no "homebrew" stuff. 3rd party material being okay.
More information about the character and his sheet can be found here: http://www.myth-weavers.com/sheet.html#id=940121
You could say this character is a parody or inspiration of Guy Fawkes. So the current build allows for a lot of interesting tricks and hits. Though he's ultimately low in the ac department, which is offset by the virtually high miss rate the enemies get. At the moment, the build is not set in stone so I am allowed to make changes when needed.
So what I wanted to ask: Is there a way to optimize the character any further or improve him in a way to maximize his damage output, utility, and/or his feats without spending more gold, changing his class or changing his items?