i know yours is new but perhaps the pressure plate is faulty. I installed the same clutch kit into my 07 WRX and 8k miles later i have the same experience you are having with the new one. So my two cents would be to inspect your pressure plate. make sure the prongs all have the same rise. And try putting some pressure on the plate and see if you notice more flex from certain prongs vs others. I'm not sure about the play you speak of but my car is still blown to pieces so i will look and see if there is play on mine, then report back to you.