Re: "Tricky" energy and the committed attack
I had the great pleasure of training with shihan cottier sometime last year, on this course he was explaining the idea of a feeling hand. Using the front hand to guide and feel the attacks. If you stand in a good stance and have your hands out correctly you can use your front hand as a feeling hand, judge any strike that comes too close to htis hand as being a committed attack and act accordingly.
If it turns out that this wasn't the ''killer blow'' but just a prelude to it then so what, as long as your technique is effective then uki shouldn't be able to throw the final punch. To me aikido is all about acting on what uki gives you, not waiting until they get through all the punches/kicks/headbutts they wanted to throw at you before you act.
My two pennies worth