Primordial Life is interesting, however I think that evolving such a creature would be something to aspire to rather than have it built-in. I do think, however, that certain substances, such as chlorophyll and muscle, will act as a sort of substitute for these "body parts".
Well, in nature, don't different bacterial species have different shapes as well? In fact, if we want true multicellularity, then doesn't that require specialized tissues, with specialized cells? Besides, it will make it far more interesting, even at the single-cell scale.
Well, no I wouldn't take bacteria as a good example for different shapes. Diversity in shapes overall between animals, plants and fungus is there anyway, I just wanted to nitpick .
Substances like chlorophyll will as I see it make for a big part specialised cells. They are the reason after all leafs are green.
So, I am sorry for missing your point. What did you meant?
Well, basically I meant that I don't think multicellular life could have gotten as complex as it has if all our nerve, muscle, spleen and skin cells were just rods. Letting a gene control bot shape would allow you to let algae evolve a large surface area, for example, or let multicellular animals evolve all the different shaped cells we have now.
Also, I don't think it's practical to give every cell the abilities we do, like to see. This is, first of all, nothing like real life. They should have a gene that controls the ability to respond to light/sound/smell/whatever for a cost. That way, there's also less processor consumption and an incentive to become multicellular, so you can sense as many things as possible, since each cell can only do one.
Just a thought.