imo u shouldn't get your STR so low, if u remember u get skill mastery as a passive in 77 lvl's, which is influenced by strength. Try to balance it a bit more.
Now about PvP's in general, u should be equipped with a bow (e.g carnage mana up suits just fine, or Peril with QR +6+++), and the rules are simple. Kite, root, heal, etc etc.
Now in oly, first you have to see with what class you are up against. E.g if you are playing against a Fighter-only class (no drains, no reducing speed spells), use only your fighter buffs. In that way you can save MP for root or bow attacks.
Next step, u have to see if u play against a melee char or ranged one. Root is kinda useless to archers, cause their range is 900 while yours 600, so, u cant kite them. U should only root them if u want to heal your self or run away while waiting for the match to end.
Mana burn is useful to all kinds of classes.
So, with the above, your gameplay should go like this:
Against melee classes: Root, mana burn, block ww, block shield, and kite to the death.
Against archer classes: Majestic robe for stun resistance, mana burn, block shield and kite to the death
Against mage classes: ALWAYS USE MENTAL SHIELD. Mystic Immunity does not last forever. Mana burn, NM light for sleep resistance, m def and atk speed, block ww, and kite to death xD
Now, there are some classes that u just cant kill. Dreadnought, Grand Khavatari, Duelist, Shilien Templar are probably some of them.
I won't speak about Titan, with him it's all about if root and 4-5 mana burns succeed. In other words, all about luck. :)