I think this project is amazing as well, and I really enjoy using it as my preferred method for coinjoin txs. However I do have one complaint. The other day I was using the sendpayment.py script. The command was exactly:
python sendpayment.py -C -N 4 0
The script put the transaction together, and presented me with the options and a "y/n" prompt. I pressed "y" without paying too much attention and ended up paying some asshole 2.8 BTC to send a little over 5. Which is more than half of the bitcoin controlled by my privkeys.

A couple suggestions:
1. Kick those people from the IRC with 50%+ fees.
2. Present the cjfee in something other than satoshis or have an alert that says you're about to pay an insane amount.
Thanks for the feedback. Sorry for you loss.
It displays the coinjoin fee as a percentage and prints out a huge warning banner if its above 2%