How can I get more impact in my kicks? [rather than push] ?

more hip. Imagine your body is like a whip. release the kick with your leg fully relaxed but controlling its movement and at the last moment let it snap. Try to make a drumming in your lower abdomen by releasing air through your nose as you release your hip and snap the kick. The more relaxed your leg and hip is the more snap your going to get. also practice the kick a lot! kicks that push tend to be tense. that usually happens because the kicker is trying to maintain the leg on its coarse and tightens too much. the more you practice relaxing the leg the better control you get and the more power. Dont let it go limp though, just enough tension to keep it on course. sounds like your kick looks good so you know what its supposed to be like. now let it go and most importantly know you can do it. Self confidence allows you to release that Qi! Good luck hope this helps. oh and make sure to snap it back before you hyper-extend the leg (in snap kicks)... not fun. also if all else fails. get a rope dart. did wonders for me. the faster you get the dart the better you kick!