Ond of the great advantages of leveling as moonkin is the 370% additional armor. Makes you able to tank alot of damage. Then again, if you're using the Cloth Heirlooms, you will lose abit of that armor, instead of using the leather ones.
And just abuse entangling roots, all the time. Can't count how many times it have saved me when i leveled.
And on the move, you can just moonfire spam, so long you're not glyphing for it.
Have to agreed with though that Feral is easier to level as, but not as fun. Of the 5 chars i have leveled, moonkin is the most fun i've ever had during leveling.