My apologies for taking so long to respond.
Attached is the layout with my changes. Here is what I think:
The Trackball, P1 joystick, P2 joystick, P1 buttons, and P2 buttons are fine where they are.
The Asteroids Left/Right and Thrust/Fire buttons were too far apart which would fatigue your fingers. I moved them closer together and I moved the whole Asteroids button layout higher on the panel to give your hands room to rest on the CP without hitting any buttons.
I moved the spinner up a bit and left because the mouse buttons where they were would be a problem reaching around the P2 joystick. I moved the mousebuttons left of the P2 joystick so they are easy to reach. I would like them higher on the panel, but that wouldn't leave enough clearance for your hand to play Asteroids.
I moved the left 4-way joystick more left to clear the P1 8-way joystick and moved both 4-ways up on the panel to give you more room.
I moved the Admin buttons left and right to make room for the Asteroids buttons.
If you click on the image attachment it will open full size on your computer.