Bit of a necro post, sorry.
Corpse eater makes build choices silly if you could say get adrenaline/first aid without having to invest in that attribute. It isn't just saving a skill book purchase/theft, it's saving you an attribute point that can be placed somewhere else. This is broken to me and if more corpse eater abilities show up with further acts the number of optimal builds utilizing elves would beat out the other races easily.
With that said, despite any feelings towards corpse eaters balance I do think it needs to either be reworked or replaced because it's wasted healing and skills to not take at least one elf in a group and multiple elves start clashing due to them both wanting to eat the flesh. Perhaps it would be interesting to strip the consumption component and allow it to act more like a book to be read by elves and then only allowing the use of abilities if you meet the normal requirements to learn them.