My opinion on some of your questions.

#1. The advertised range of the Naro is farther out (1000' vs 500') so I'd go with that. If your Tx allows it, you'll eventually be able to do flaperons and other mixes.

#2. The 400ESC will be enough. 15 AMPs continuous, 25 burst. The difference is how many amps they can handle. The larger the number, the more amps. My only concern is that the E versions of the ESC have a lower voltage cutoff: 3.2Volts as opposed to the other GWS escs that have a 4.2V cutoff. I'm not the battery expert, but I'm almost sure that you'll have to monitor your own packs and not trust the ESC to cut the engine for you.

#3. From the reports I hear, the 400 begs for a 9.6V battery. That said, I've seen the GWS 400 Tiger Moth fly on a 8.4V battery.

#5. The difference between the servos is their size, strength and the amount of torque they output. I'd recommend the Naro's only because they are the same size as the Hitec 55's which many use.

Good luck with your Estarter. I'm putting mine together now. Should be finished by spring at the rate I go.... [] Good thing I've got 2 other planes to feed my need.[8D]