RE: Balance Point Determination
Please read the article at RCSD linked from my website called "Sailplane Calc Article/Tutorial" and it will enlighten some things about aircraft balance. Also, sailplane calc works on most planes and it's a little conservative, not much but it makes for a nice safe handling model on it's maiden voyage.
Lastly, you cannot accurately balance a model without knowing the area of the horizontal stabilizer and the distance the horizontal tails quarter chord location is from the main wings quarter chord location. Anything else is back to basic rules of thumbs which in some limited cases works well.
Curtis