Personally I take 10% more constant damage and 5% more reduction over a ~10-15% higher chance to do 50% more damge some of the time. Only fury warriors should crit stack IMO since their mechanics revolve around it.
You're in prot spec right now(jelly of your mara shield T.T) But looks like you have everything if you aren't going for a green lens. I see a lot of ret pallies with
The Pacifier - Item - World of Warcraft, maybe give that a whirl if you're feeling adventurous.
I suggest whirlwind/Tclap glyph for arms over shattering throw, unless you're going into arena and you know it's against a mage/pally.
Looking good
Ideally you'll want at least 7k, anything below that and you might spike too fast for healers to react since you're going to be one of the most prominent targets at times. Defensive stance makes your stam more effective, and enraged regen + battlemasters will help in a pinch. Just remember your stances and not to charge in too deep, you'll get a feel for how much punishment you can take after playing around for a while.