Maximum timing advance is your only concern.----Timing at idle looks after itself.-----If you have issues with idling the first thing to do is a compression test.----Post the actual values here.
I was thinking about you yesterday Racer.
A guy asked me about his motor and said have you done a compression test. He a bit defensive and ask why does everyone say that.
I simply said well the first thing they do when you go to the doctor is take your blood pressure.
It the first step in leading you in the right direction.