And even with your -1 idea they still suck. A wizard could cast 20+ spells no problem (other than corruption) at 10th level. A cleric might cast two and be almost useless the rest of the game. If this is a way to limit spells like Resurrection that's a nice idea, but when the main source of fun for a class (in this case spell casting) could be limited to one or two successful casts, I wonder if this is the right way to go about it.
Which is why I recommended the Cleric be given an Attack Die of sorts. Either a lesser version of what the Dwarf and Warrior get or one that only applies in certain circumstances (like against creatures that offend the Cleric's deity).
This would make the Cleric more Fightery. More like a traditional Paladin than a straight Cleric.
But it would also lessen the need for the Cleric to be strictly a spellcaster.
I get the idea of sacrifices. But I think long-term that could get annoying because it will be driven by numbers, not necessarily story.
So instead of the "15 minute workday", DCC adventurers will just have a sacrifice every 15 minutes.
"Whoops, almost out of healing. Got something to sacrifice?"
Not a terrible byproduct of the rules. But I could see where it could get so routinized as to be considered more of a hassle (like tracking encumbrance) than cool. IMO, the Cleric doesn't need any more hassles.
EDIT: The 4e Artificer has a similar "let's make a sacrifice so the party healer can do more healing". After every encounter, the Artificer collects healing surges from the party to "pay for" the healing he's done. In a word, it's lame. I could see the DCC Cleric following a similar path in collecting gold pieces or items of value to "pay for" the services of his deity. If the Cleric is given some efficacy outside of spellcasting (as in a nerfed or situational Attack Die) then the player would be less likely to focus on diminishing spell power. I think it would also fit the tenor of the divine spells we've seen thus far. They appear to lack the boom of the Wizard and Elf. The Cleric spells seem more "blue-collar" to me.
So let's let the Cleric hit things too. It will save us the need for a Paladin later on.