Claw Bot fine tuning.

My team has a Vex Claw Bot, we are programming in graphical to help teach. We are wanting to program the claw bot so the arm will not release to gravity when pressing the button, ( not make it go straight down after the button is pressed ). Also we are running in tank mode, we want to make it a bit more fine tuned when moving. I have attached our program so far, its a basic command list. Thanks!
Basic Commands.JPG