I'm the one who had impulse on the throttle and warp on the buttons. I am satisfied with the controls but they probably don;t do what you expect.
Push the throttle forward and you begin to increase Impulse speed. It doesn't matter how far forward you push, the throttle acts like the up/down arrow buttons, not like a real throttle. If the captain doesn't want the ship to go full speed then when you reach the desired speed Helm must set the throttle in a neutral position.
Hold the first button and you get Warp 1. Release and you immediately drop out of warp. The buttons for Warp 2, 3, and 4 work the same.
"Damn the torpedoes! Four bells, Captain Drayton!"
(Likely actual words of Admiral David Farragut, USN, at the battle of Mobile Bay. Four bells was the signal for the engine room to make full steam ahead).