Woah that's a pretty excellent calculator! Whence did it come? I wish I got paid 26 times a year... it's actually every 1st and 15th, so only 24x. I do get bonuses though, so maybe that's close to accurate still.
Your assumptions were correct for the most part. I file single, am single, no state taxes, claim zero (even so I have previously always owed). My spending is at about $29k/yr before my CC payments. $41.5K/yr with the CC payments.
My big glaring sore thumb right now is that housing expense. I want to either reduce it with a roommate or turn it into an investment with a fourplex.