Combat healing, as a rule, shouldn't be that common. Let the party stumble across a cache of powerful heal potions, and leave it at that. If they suck down good healing when it's not vital, it's their fault if they don't have it when they really need it. Two or three potions per character should do the trick.
Energy drains and the like will be a royal pain. Make sure that they're in really good with a local temple, and well-enough known locally that they can get poisons and other conditions healed without too much hassle.
And try not to overdo the opposition. Since the party is cleric-free, you don't have to worry about lots of little creatures being of no consequence; hits last until the party properly deals with them. Give the party plenty of opportunities to run away when things look too bleak, and let them rest up to come back when they're more ready.