I have used it on interiors with no ill effect. I dont do it often but I dont see the prolem its a very safe APC.
As for dilution rations:
On engines I use it straigh, if im usig it on wheels its normaly straight or 3 parts apc to 1 part water.
I also use it as a pre wash. I mix it 10 parts water to 1 part apc. This is really really week and is just desgined to help lift the dirt. I throw it in a chemical sprayer and mist the car. If you mix it this much dont expect miracles, thats not what thi ratio is for
However like I said on bad places like engines and wheels straight works really well.
Like any apc it will strip wax. Depending on the ratio wil effect hwow much was it srips.. but its and apc so yes it it ill strip wax