I can't help with the DIP switches, but those pots look to adjust the distances that the claw travels. Not sure about VR4 and 5:
VR1 = forward / backward
VR2 = up / down
VR3 = right / left
VR4 = ?
VR5 = ? extend?
The machine looks great - my wife's crazy about these claw machines; I had no idea DIY kits were out there.
Yeah...those pots are probably limit adjustment and I am almost positive that those dip switches will need to be set to send the correct current and micro stepping to the 3 motors that drive the claw. Generally, but not always (especially when working with a traditional stepper break-out board) switches 1 thru 3 control current, switch 4 will be current on or off when no signal to stepper and 5 thru 8 will control your micro steps (this is assuming the motors that drive it are stepping motors and not just regular mini DC motors).
Actually...looking at some closer pics on Aliexpress, they seem to be just simple DC motors with limit switches, but I see they come in 12V all the way up to 48V, so you might want to hook up a volt meter and see if changing dip switches 1 thru 3 from all "on" to all "off (or a combination of) actually changes voltage. Check the side of the motors and see what their specs are and go from there. If these switches control voltage, then the other switches might control other items like motor speed, holding torque...etc. Once you are sure of the voltage setting, you probably can't screw machine up with the other switches...these are more than likely tweaked by operators to make sure people don't win anything.
These are all just guesses...I am no expert on anything.
Paint looks good...