Remember, Brambles also buffs your Entangling Roots damage, making it a respectable DoT, and Nature's Grasp will be trainable with 100% base chance to proc. There's a Daze effect proc as well, with huge implications for AoE grinding.
Also, Starfire is great for single mobs, but for multiples you'd use it pretty much solely to pull, then use DoTs and Wrath to burn everything down. I have no problem letting things beat on me in Moonkin Form, especially with Thorns reflecting 80+ damage a hit now at 70.
Nature's Grace will reduce the GCD on Wrath too, so you will be able to chain 1 second casts with sufficient crit.
Oh, and Starlight Wrath has reduced SF cast time since it was introduced in 2.0.
I posted my planned level 70 grinding build in another thread; I'll take a fresh look at it tonight.