So we ended up with me (34 warrior), a 31 warlock (the leader), a 30 rogue, a 29 hunter, and a 35 mage. Clever WoW strategists will note that the lack of any type of healer among those represented.
I think we were all a little dubious about how it would go, but we decided to give it a try--particularly because it had been so hard to recruit this party. (And the graveyard is so very far away from the dungeon entrance.) For me, at least, part of the thought process was "Well, maybe we'll clear a bit and manage to pick up a healer--and if we die, it's no one's fault."
We cleared the whole instance without a single death.
The basic effect, of course, was that we were compensating for lack of healing with some careful planning, a lot of crowd control, and superior damage-dealing. I don't think we had anyone break a sheep or a sap in the whole run. We had about three cases where we got monsters above and beyond the original plan, but in every case we handled them well.
It also really helps that Razorfen Kraul doesn't have many large groups of monsters. Almost all the groups were two or three monsters, so Sap and Polymorph really cut down the damage influx.
And the roleplaying in this group was outstanding. I'm not sure whether the leader was picking from a group of roleplayers, or just setting an example that we all followed, but it was great. The leader had a great snooty blood elf style, and as we proceeded through the bat area, there was this continual sniping back and forth between the blood elf warlock and the troll mage.
I did have some trouble contributing to the roleplay, because I'm having trouble finding Roktazza's voice. In particular, I don't know how to translate "sap triangle, pulling skull" or "cast Dampen Magic on me again, please" into Rok's earthy vernacular. And the other roleplay-inhibiting factor is that it's very hard for me to type while fighting with the warrior, because I need to hit action buttons a lot. Mazumok (my hunter) has it much easier; if I autoshot for five seconds while typing something, little serious damage will occur.
As a tank, I was doing fine with holding aggro (69% of the damage taken, according to my Damage Meters), but I was having some trouble with rage flow. I had in mind that once I'd established aggro, I should use Shield Block every time it was on cooldown, to avoid more damage--but I rarely had enough rage for it.
Another amusing note: because I used healthstones twice, drank a potion once, and bandaged myself once, I ended up topping my Damage Meters for 'healing done'. There aren't many runs where a warrior can say that--at least, not many successful runs.
This makes me wonder what other instances could be run by an appropriate-level group without healing. I can't imagine running Blackrock Depths or any higher-level dungeon without healing--but I was surprised by our success with Razorfen Kraul, so maybe I'm just too skeptical.