I thnk it's a 5x3 or 5x2.5. Whatever the Cox grey 5 inchers are anyway. I don't think anyone has anything better than these. If you can't find them then I'd say an APC 6x2 cut down to 5 would be fine. Or you can try an APC 6x3 and cut that done to 5 but taper the blade width a little to help the rpm's stay up there. It'll be a real screamer with that engine.

Not very much. Small models are flitty at best. I'd say about +- 3 3/32 for the ailerons and no more than +- 1/8 for the elevator. Especially at your speeds. Go for more later if that's not enough.... or even less if you're nervous.

No landing gear. It's added weight for nothing on these small models. Not just the wire but the structural details required to keep it from ripping out. It all adds up quick on the small ones.

Don't crash.... If you need to know anything about the first flight then this isn't your kind of model. Oh, OK then. Since it's on draw then don't THROW it. That can starve the engine. You want a gently accelerated push from way back there to out here and then release with about a 20 degree up angle. More like a guided javelin toss A helper you trust to launch will let you keep your thumbs ready. Don't bother running with this one. It'll just confuse ya.