The GWS 4530 should be a good prop for the setup David, with your 2300kv motor. I would think the motor should be fine. Depending on the kv, you could use a 5030 or 5040 prop on 2s, but given the added current draw the returns are diminishing. With a slightly lower 2000 kv motor, the 5030 and 5043 are certainly useable on a 10gm outrunner, but there's probably no need for the added thrust on your model. While I like scale sized props on models, the smaller props have a lower P-factor "torque effect" also, which makes flying them easier. As you go larger, the right thrust angle really has to be tweaked to offset the left hand turn tendency caused by torque effect, if you want the model to be reasonably flyable. I have a Guillows Spitfire with a scale 9" 3-blader that has an insane right thrust angle. Once properly set, it turned out to be a good flying model, but a smaller prop would have made things easier.
A good CG setting would probably be around 25%. These high wing, ideally proportioned trainers are the only planes where I'm bold enough to go further, such as on this model. With some of the warbirds, I wouldn't have them anymore if I had flown them at 29-30% MAC.
For whatever reason, a number of people on the forums seem to suggest dangerous aft CGs, which I certainly haven't had success with. A lot of the plan CGs are picked out of a hat also.
The bipes are really fussy. The Guillows Sopwith for example flies beautifully with the CG at 10mm from the LE of the bottom wing. Don't even try it at 15mm, unless you have really tall grass/weeds like I did, when I first tried it at that setting.