ok ive heard that taking the mesh screen (throttle body screen)out of the throttle body improves airflow, but ive also heard it servs a very important purpose, which is preventing turbulant air fromflowing across the air flow sensor. so is it better to take it out? or leave it in???

The main reason the screen is in the Mass Airflow sensor is to shield the heating element from any potential debris. But this is based on the assumption that someone would be clueless enough to drive without an air filter. Any HP gains would be from the somewhat smoother airflow from the absence of the sreen.