As long as you have 7 or more life, damage that would reduce your life total to less than 7 reduces it to 7 instead
According to 17lands data, Orzhov is ever-so-slightly ahead, 0.8% to be precise
Hakbal of the Surging Soul You could say ramp and card draw are the most important keys to victory and Hakbal of the Surging Soul gives you access to both, maybe not in the same turn, but both is more than most color combinations can say
Pramikon, Sky Rampart beat it to the chase, but The Walls of Ba Sing Se feels more appropriately wally
Collision of the Realms Chaos effects are a controversial topic in Commander
Reds allied colors are black and green, and it shares an affinity for menace with the former and trample with the latter, while it shares access to first and double strike with white