Yea, it's built like a tank. Don't worry too much about it. I thought mine was pretty heavy too, but it feels very light in the air. Maybe because of the lift from the rotors.

I'm no expert, but a .46 is way, way, way too much. I used an ancient almost worn out os .25 and it flies well at 1/4 - 1/3 throttle. Altitude is definitely controlled by throttle on this baby, as it climbs like a witch at even 3/4 throttle on the .25. Plus I think there might be a ton of tailweight issues with a .46.