What about those eel things on the photon tubes surface ('these were microbes on the tubes surface we mustve shot them here from Enterprise') those things disturbed me almost as much as the Ceti eels (no doubt included to give III the yuk factor II had) even David's description of them was icky ('they were fruitful and multiplied'). remember in 84 I initially thought they were something to do with Spock dead body (his mutated blood seeping out the photon tube or something hideous)
I Thought the original microbes (the one from David Marcus's interpretation) looked like a plate of pasta and tomato sauce.... oddly by the time the Klingons show up they looked more like Tape Worms