Semi-symmetrical wing, ( just for funnies, there is no such animal as SEMI-symmetrical, however since we know what we mean using the term, let's just do it. OK? )

If you have the wing and stab (assuming a flat or symmetrical stab) at 0° angle of incidence relative each other, then moving ailerons will simply screw up your flight characteristics in different attitudes, maneuvers, and airspeeds. Now when you really learn your machine, depending on the flying job you are performing, some of that may be good.

If you try to adjust with strictly forward CG, (forward of 25% MAC) you just might end up with a model that will be very stable to a point, then fall out from under you as you retard to idle during the final landing maneuver, as the elevator runs out of ability to hold the nose up in a flare with idle engine airflow and especially if the model lands slowly, or if you have to apply a significant amount of up-elevator to hold the nose up, then that can call the stabilizer to stall out on the bottom side. It is using the same airflow-rules that govern the lift of your wing.

The semi symmetrical wing will offer some of the characteristics of a flat bottom wing, but not so much at a given time or place. As others above have said, when the engine is given additional power during stable level flight, the accelerated airflow provides instant lift over the wing increasing some additional lift within its span plus a little. Then the airplane accelerates also in airspeed, thus providing additional lift due to the fact that lift is a function of the square of the airspeed. This creates a climb attitude as long as power available is above power required.

In determining "incidence", downthrust, etc. I suggest you consider the chord-line of the stab to be at 0°. Use that line as the base line. That center line on the plans which was useful in building the fuselage is not understood well by the aerodynamic critters. Stab line is. For example a plan may show 3° positive wing incidence, 1° positive stab. and 3° negative downthrust. Aerodynamically you have 2° positive wing, 0 stab, and 4° downthrust.

Therefore the best solution, used by FFers and hi-wing trainers for many years is the simple downthrust. You can, via experiments, find a downthrust setting that will, when throttle is advanced, tend to pull the nose down to offset the climb from additional lift.
When you get the airplane trimmed at level flight with a good cruise power, when you get the Down Thrust right, it will pull the model down when power is added and stay close to trim, then when you start retarding power for the landing / slow flight, etc. the pulldown goes away and the elevator will very likely be set for a good glide with minor adjustment.

Once you get these basics all squared away, then you just might have fun trying to find out what changes in incidence, CG, and changes in thrust settings can do for you. That is where you learn the most.

Then comes the real downer. In some 60 years of modeling, when I think I have it all figured out, I build something that totally deletes all those HARD FACTS. [:-] So experiment a little at a time and have fun.