Oh, I also forgot to mention that ... the CA's do scale with your level, our damage spells do not. Our CA's do more damage than our spells, are faster to "cast" and less prone to misses (resist), most of our CA's also have DoT's on them too. (More so than the spells they "replace"). Also one other benefit is that you do not need to upgrade those CA's every 10 levels (or so, depending on expansion) ... that is 5 spells you never ever need to spend money on to upgrade. (although I use 2 spells (purifying flame or sanctifying flames and the AA spell Divine Demonstration (cleric, wisdom), mainly for pulling mobs, if they survive)
There are many things about Inquisitors that are not where they should be but CA's is not one of them. (Buffs, debuffs, healing etc needs a boost). I am specced for soloing and doing great having no problems whatsoever. Ofcourse, I am constantly in our offensive stance (more CA damage, less healing). Perhaps you are in healing stance? (less CA damage, more healing) (stances are unlocked in AA, shadows ... Litany of Combat (boosts damage) and then the stances is shadows -> persecution (offensive) / Redemtion of Faith (healing).
In order to get Max out of Melee as Inquis, you need to spend AA's to properly set it up. Feel free to check up on my AA setup ... it's not the best or maybe not even optimal, but it works great for me for what I want out of it.