1. Chris Kyle was in the Army, he didn't have the luxury of choosing a rifle. He used what they gave him.
Chris Kyle was a Navy SEAL, from what I understand just about anyone in SOCOM these days uses whatever the heck they please, their armory is like a buffet... Pretty much everything else in your post I agree with though.
Sgt. of Marines, 3rd Award Expert Rifle, 237/250
1st Award Expert Pistol, 382/400
D Co, 4th CEB, Engineers UP!! OEF 21JUN-20SEP2011