I really ought to stop posting in my own thread, but...
After adding the [CURIOUSBEAST_ITEM] tag and changing their body type back to the one-piece-with-many-chunks configuration, the oozes still retain their relatively cowardly behavior. One of them stole some fish I had embarked with and made a beeline for the edge of the map (slowly, granted), while the others wandered around critically wounding my pets and not drinking my booze. Perhaps my organs-for-eating theory wasn't too far off; barring that, re-adding the secondary mouth part.
Hilariously, also, one of the oozes had all of its Chunks ripped off and its Core mangled by a dog; shortly thereafter, however, it healed up and started moving again. A pack of five amateur wrestlers, a miner and a woodcutter, however, managed to kill all of them with no casualties.
Having an attack whose only damage type is [BURN] seems to make them mangle and injure only, but never kill; this may need to be remedied by changing the type to SLASH or BLUDGEON. On the other hand, some would argue that immense crippling is a fate worse than death, so if the damage counter was increased immensely...
I'm not sure if there is any way around the inherent cowardice of the [CURIOUSBEAST] tags, so this may end up being something of a failed attempt; however, I have yet to see what happens when I bait them with constructions to destroy.