The free will argument demonstrates that christians don't understand free will.

[Coffee Jesus]

Secondly, since it's the thought of sin that'll convict me and not the act, we're still left with a scenario in which god could prevent evil actions but not thoughts; he knows what we think anyway, and the only result of this system would be a net reduction of needless suffering.

I thought, errantly, that MFM was posing that evil has to be possible for anything to be truly immoral. The Christian could say that immoral thoughts are immoral because they create a setting in which evil is more probable. Hence there would be no immoral thoughts unless evil was possible, or at least seemed to be possible..