Here's part of the answer....
1) CG position ? Between 25% and 33% of the mean chord is what I used to use. As Mad Flight Scientist suggests, there are better ways, and somewhere I even had a generic equation that was intended for model flying, but 25-33% is a fine start for "normal-looking" tailplanes.... Beware using actual airliner dimensions as you'll find them a bit under-tailed by model standards.
2) The other problem, finding where that's actually located on a swept wing aeroplane ? Here's a method for you.
i) Make yourself a scale drawing of the wing planform. One side of the aircraft (port or starboard) will be sufficient. Approximate the planform to four lines: the tip and root chord to be parallel to the aircraft centreline, leading/trailing edges make up the other two lines.
ii) Measure 50% of the root chord and mark that point. Measure 50% of the tip chord and mark that point. Join those two point with a straight line. Call it "Line A."
iii) Project a line in the forward direction, parallel to the aircraft centreline, from the leading edge at the root chord. This line to be the length of the tip chord. Let's name the point that it reaches "Point B."
iv) Project a line aft from the trailing edge at the tip chord, again parallel to the centreline, the length of the root chord. It will reach "Point C."
v) Join Point B and Point C with a line, Line D.
Where Line D intersects with Line A, you've found your mean chord. That is to say, the chord section of that part of your swept wing is equivalent in CG location terms to a nice constant-chord plank wing stuck through the fuselage at that point. So, measure 25-33% along that chord section, project it back onto the fuselage, mark it as forward/aft cg limits, and Robert is your avuncular relation.
As MFS said, if this chord section doesn't come out "somewhere about 40% outboard from the centreline" then you or I got something wrong.
This method can be used for wings with different degrees of sweepback on differing panels. However, that's not a description you want me to type out.
It worked on my pusher canard delta (which flew a circuit and a half before the fin fell off and I went to Polyversity...)
Caveat emptor: it's ~20 years since I designed and flew models, ~17 since I completed the degree that taught me how to do it properly, and I'm now a consultant giving strategic advice to senior managers in the industry. So you might want to ask someone who knows what they're doing... and hasn't damaged their memory with several years drinking in Eastern Europe
Y
PS. Unless your model is accomplishing something that will make the evening news, I don't think you'll need to worry about Reynolds numbers.