"that he enjoyed arguing with"
With whom he enjoyed arguing (but since this sounds stuffy to a lot of people, I'd encourage you to consider poetic license).
"but it was so tight that Derek could barely breath."
Breathe.
"so much so that management had tested him for drugs twice."
This is hysterical.
"hard not to loose his temper"
I think you mean "lose" his temper. However, to "loose one's temper" is to "deliberately set one's temper loose and let it run wild."
"a coworker, and because she had already filed a sexual harassment complaint against another guy"
You dont need a comma before a coordinating conjunction unless the conjunction is followed by an independent clause. Since "and because she had filed a sexual harassment suit against another guy" couldn't be a sentence by itself (because of the "because"), no comma.
"old looser with a drinking pro"
loser
Crud, this is funny.
Author's response
Thanks again. About the coordinating conjunction, I’m working on using something my grammar teacher talked about where you put excess information inside commas. Not sure if I’m doing it correctly but I’ll clear it up this semester in creative writing class.