Thorns returns utterly pathetic damage in pvp (ask SiP I believe he was the one who tried a lvl 2x thorns pally). It's something like 1/10 the damage returned. Smite, however, deserves one skill point; many do an attack order of smite, sac, smite, sac, etc etc etc.
Defiance is useless. The point in Smite is just to stun -- you'll only do a few pts of dmg after the PvP penalty. You're not gonna actually kill anyone doing the sac/smite/sac/smite thing unless they're really slow with the juvs, but it'll win you duels (you don't have to kill someone to win a duel). If you just want ears, stick with sac all the way.
Might i suggest making a more effective build since you seem to be pretty unexperienced with lower level dueling. Its not exactly easy to make a good level 9 sacadin. Perhaps a jabber kicker or charger?
with 1.10, there isnt much variety in low level dueling. sigh :yawn: