Well cleric imo has 2 main problems concerning damage. Firstly the available weapons SUCK - period.
Secondly and more importantly clerics have to rely on mana for sustain as well as damage. On a rogue you can just wait for your stab cooldown and quickly kill single targets, warrior has excellent aoe and powerfull cooldown abilites aswell.
Now on a cleric you lack good weapons and have skills that not only also have a cooldown, but use mana as a ressource that just as life doesnt refill by itself.
Imo to improve clerics you could give them different toolsets, heals that also heal companions which is whats planned is a good start. But also the holy warrior aspect could be strengthened. Why cant clerics use swords? If not by default, why not at least give them the ability to learn how to handle other melee weapons than daggers and maces.
For example you could maybe buff Arbeno's Might. The increase in mana cost feels too harsh, actually it would make more sense to decrease its mana costs to maybe be a free buff with a certain cooldown at rank 3, just like warriors and rogues have.
Make it a player choice to go down the path of the righteous warrior shattering his foes by brute force, or to ascend as a holy Priest, bolstering his allies. Maybe even give us the option to become a holy avenger who, enraged by the death of his companions smashes everything in his wake, possibly at the cost of taking increased damage during that period due to his recklessness.
Well, went a bit off topic here but yeah, cleric needs some improvements - and has the best potential to become the most awesome class.
