> we don't inherit any software (is that true?), we at least inherit assembly code

To stay with the metaphor, DNA could be rather understood as firmware that runs on the cell. What I mean with software is the 'mind' that runs on a collection of cells. Things like language, thoughts and ideas.

There is also a second level of software that runs not on a single mind alone, but collection of minds, to form cliques or a societies. But this is not encoded in genes, but in memes.

I think we have some notion of a proto-grammar or ability to linguistically conceptualize, probably at the level of some primordial conceptual units that are more fundamental than language, thoughts and ideas in the concrete forms we generally understand them to have.

I think it's like Chomsky said, that we don't learn this infrastructure for understanding language any more than a bird "learns" their feathers. But I might be losing track of what you're suggesting is software in the metaphor. I think I'm broadly on board with your characterization of DNA, the mind and memes generally though.

At the most fundamental level, is it even linguistic? Would Tarzan speak at all?

Children (who aren't alone) will invent languages to communicate between each other, see Nicaraguan Sign Language.