Ok so let me just point out that I'm not anywhere near that experienced as a pally tank and I'm sure that others with more experience could give you more advice, but let me add my 2 cents worth.
As far as your build goes, it's not bad, but here's what i'd change. As far as tanking goes, you don't really need any points in the holy tree because you won't really be using anything from there. If you're worried about just healing yourself, the basic spells you learn from your trainer are fine, plus protection has a few little tricks that help too.
So I'd start by dumping all the points from the holy tree which will give you an extra 15 points to play with. Now for me personally I put 2 points in to guardians favor just becuase I like the reduced cooldown on blessing of protection. Now for leveling purposes I'd reccomend going 5/5 in reckoning and 5/5 in ardent defender since that spell has helped out a lot when I've gotten a little over zealous and pulled more mobs than I can handle easily while farming.
The other change and this was a personal preference was I maxed out benediction just to help with mana issues. But yes to all those who will come behind me and say that mana shouldn't be a focus, I agree when you're at lvl 70 and tanking instances but for leveling, having a little extra mana for that last self heal is always appreciated.