It's surprising the things you'd be able to do with even quite weak TK. Gentle pressure on the carotid artery. Press a brake, or an accelerator, or some other important button. The old "tie shoelaces together" trick. One favourite of mine is if some idiot has a gun stuck in their waistband, pull the trigger. But that lighter fluid into a vapour trick is rather a good one, very subtle (although the results sure aren't).