Initial timing set @ 30*. Engine seems happy?

Idle and timing are two separate animals.

Yes, idle will change when you adjust the timing. When you do change it you should adjust the carb back to base idle, say 750 - 800.

You NEED to check the balancer to be sure it's accurate. Piston stop at TDC and see where the mark is on the balancer. Then you will know for sure if you are setting it where you think you are.