I saw the play too and mostly agree with your thoughts. I went because I'm a Marin Ireland fan and I did like her more in the role than you did. There was a play a few years back called This Wide Night (I think?) with Edie Falco and Alison Pill about ex-cons trying to make it after being released and I think it dealt with the same subject matter as Kill Floor in a more effective way.
The play is way to scattered and unfocused. There are so many subplots that there actually isn't really a main plot to follow, but rather a bunch of (at times unrelated) loose threads to try to grasp onto.
MINOR SPOILERS*********
I didn't think the son's struggle to come to terms with his homosexuality was necessary to the story and I strongly disliked the white rapping stuff. That whole subplot was trying to tackle like 10 different issues in 10 minutes.
END MINOR SPOILERS***********
The best stuff was watching Ireland self-destruct at every moment. The way she never took responsibility for her problems, grappled with her rage, etc was effective stuff. I actually enjoyed the scene with her new "friend" at Dairy Queen. Ireland was a trainwreck and I felt for her.
The ending (or non-ending as you correctly said) should have been rewritten. Personally, I wanted to see her really screw up at work somehow and possibly get arrested again. Even though Ireland was her own worst enemy, she was also trapped in a system where she was never going to succeed.
I completely agree with you about the use of discmans and CDs. Was this taking place in the 90's? Also, I found it weird that the son kept calling his friend and leaving voicemails when most teenagers would be texting, right? Especially about pot and fooling around? I too won't be seeking out Koogler's other works, but I'll always be down to catch Ireland's next performance.
Marie: Don't be in such a hurry about that pretty little chippy in Frisco.
Tony: Eh, she's a no chip!