I noticed a few "bad trades" have been canceled once addresses have been confirmed. I am probably not the only one who feels this way, but shouldn't the "cancel" feature be disabled once a agreement AND confirmation has been made? This would eliminate double crossing by accident AND give ground for bad trader disputes/poor feedback request.

I wouldn't say that full-on disabling it is necessarily the way to go, although I do agree that something should be done. I only say that it shouldn't be disabled because some people are actually civil and realize that things happen/come up and trades sometimes need to be canceled with no hard feelings.

Maybe changing it to a "Request to Cancel" after everything is confirmed, and then the other party has to agree to cancel it. That way it is the best of both worlds; you can still cancel if both parties agree, but it stops a lot of the hullabaloo that people are going through.