You would decrease your DPS to the point you will fall well below sorcerer, NB and even templar that plays ranged. Engulfing flames is melee, meaning you would lose group utility, burning embers is melee, so you'll lose a high damage ST DOT and flame lash is also melee meaning you'll lose a hard hitting and possibly free spammable skill. From range you can only cast eruption, blockade, force pulse and heavy attack. Since clench is awful DPS even with master destro you'll be hard pressed to find skills to put on your bar.