Well, let me start by saying that I have a soft spot for improv comedy folks! I ran the improv club at Kellogg for a year.
Yeah, your undergrad GPA will be a weakness. Did your GPA improve over your four years in college? Ideally this is the case. If not, then those classes will help a lot, but you will still need to convince adcomms that you have the intellectual horsepower and (more importantly) the discipline to do better this time around.
Also, we usually meet people who are too obsessed with their GMAT score, but given your undergrad grades, ideally you can boost yoru score at least into the high 600's.
Your extracurriculars and involvement sound good. Your main weakness is that undergrad GPA. Hopefully you can boost your GMAT, which will help a lot.
Scott