My brothers dowell broke in half during flight. It was reduced back to a kit after that! If you are building it from a kit, and feel comfortable making some mods, then make it a bolt on wing. If you use 12 or more rubber bands, then a nylon bolt will give you just as much break away (or more), and is much more secure. My dad and I changed my trainer over to bolts and I haven't regretted it since. Of course, I don't fly it as much anymore, but when I want to, it's nice! This requires a few mods, so if you're not comfortable with that, then stick with the rubber bands. I might suggest changing dowells every few months or so. I think after they get fuel soaked a few times they get weaker. Don't use dowells you find at lowes or other places, they don't seem as strong to me. Maybe they are, but they don't seem to be. Go through the manufacturer, or LHS.

I would definitely start with the black master air screw props for a few reasons. First, they are cheap. Second, they are not as sharp as the apc (or spinning razors), and third they are not nearly as fragile as either. If you go APC or wooden later on, you'll need to go down a pitch or two from the MAS because they don't flex like the MAS props do. For example, if you turn an 11 x 7 MAS, then you might want to go to an 11 x 6 APC or wooden. Your engine might handle it, but my .46 trainer engine loads too much with the higher pitch APC and wooden props.

As montague said, you need to find the correct spinner nut for your engine. If possible, though, I'd simply slide the battery as far forward as possible, and if that doesn't do it, add a little bit of hobby weight under the fuel tank or something like that. Try not to put a heavy prop nut on that little engine. It simply adds mass that the engine has to turn, and you loose some of your power that could be transferred to the prop. However, sometimes a prop nut ends up being the best way to balance a plane--whichever works for you. You definitely do not want a tail heavy plane. Nose heavy planes fly, tail heavy planes crash....