You can dim the lights now by using your remote control and the ir543, usually the volume buttons will do this. A scene will remember 1 or more lights and bring them to a programmed brightness, all by sending 1 code from the remote.

You are correct about how to set up the scene using the maxi controller, after the clear sequence, you set each light to the desired brightness, then from the maxi controller send M16, N16, O16, P16, then send a new address which will be the scene address. When this is complete, anytime you send the scene address, the light(s) will adjust as you set them up. You should find all this in the manual.