Without knowing the airfoil, almost everything is wild speculation.

And cambered airfoils AOA and incidence is measured from the middle of the LE through the middle of the TE, not along the flat bottom.

So don't look for good answers until some more details are known. And don't bust a gut with that indicence meter until you've got an understanding of what you're measuring.

The incidence of the wing and the incidence of the horizontal stabilizer are set after taking a number of different things into consideration. You've got to know the AOA you want for that airfoil to present the proper lift for your model weight at your cruise speed. And then figure out the downwash from that wing and what of that downwash the stab is going to see. And then take that stab's performance numbers into consideration to set it's incidence.

Or you could look at the plans and match up what they show.