Rephrasing the Ship of Theseus in less accessible language, and concluding that there is no spoon (to mix references) isn't the kind of engagement that leads to deeper understanding, though. Neither is the conflation of senses of "individual" helpful.

You can interact with modern science at a poetic level, which is fine as far as it goes, but nothing you've posted indicates anything deeper than that. And poetry, while inspirational, has a tendency to be wrong when dealing with nonintuitive phenomena. It has a tendency to be wrong both ways, both over- and under-estimating the relevance.

I'm well aware of the principles of quantum mechanics. The observer and the observed don't constitute each other. They interact, and the interaction is not without consequence, but that's a far cry from constituting each other. There's nothing philosophically profound here unless one hasn't kept pace with science. If you shine light on something to see where it is, of course the interaction of the light with the target might change the target in some way--in a completely classical description! One might have hoped that one could use ever-gentler means of inferring what was happening to have completely nonperturbative information-gathering, but nope! And one might have hoped that particles were smoothly graded in all quantities, but nope! Quantized, and you gotta interact to learn something (for details, see something like http://theory.caltech.edu/~preskill/ph229/notes/chap2.pdf and following chapters).

This doesn't have terribly much to do with individuality, however. You don't even need a mechanistic description of how consciousness works in order to know that brains do things including make you you. You don't need to know how internal combustion engines work in order to know that the supply the power for your car (assuming you don't have a plug-in hybrid or electric car or hydrogen fuel cell etc.). You simply note: break the engine and the car doesn't work, and it doesn't work in the specific way that it has no motive power. Brains break in specific ways too--read Oliver Sachs or VS Ramachandran for some accounts--and in this way we know that consciousness is a product of the brain, and so is personality and individuality even if we don't know yet how it's built.

And it really doesn't help, upon noting that we don't understand consciousness very well, and also don't understand quantum mechanics very well, to decide that they're the same thing. There are a bunch of reasons to think not, not least of which that QM doesn't present anything that looks like a solution to the supposed hard problem of consciousness, and if the hardness of hard problem is actually an overstatement (e.g. you side with Churchland as I (mostly) do), then you never needed anything exotic in the first place.

In particular, Fisher's formulation--I confess I do not possess the skill to adequately assess whether the mechanism is plausible, but I do wonder if he has the skill to adequately assess whether the mechanism is plausible: the article contains rather few calculations, and seems to neglect the complex environment of the cell and the rather peculiar requirement that the phosphate-containing molecules somehow couple their nuclear spins to each other despite tumbling too fast to lose coherence due to water--and that all of this would be useful for anything at all given the already-known voltage-gated ion channels, neurotransmitter receptors, and so on, which together are quite effective at explaining the observed properties of neurons.

We don't need to presuppose anything about the existence of individuals. We just observe what is out there, and go oh! There are these things! They have brains! They do their own stuff! Let's name these things! They're individuals! Huh, I'm one too.

There's not necessarily a problem with circularity, either (c.f. coherentism). If you can avoid it, great! If not, well, if there isn't a second circle that is also fine but contradicts the first one, it may be that the first is okay.

But in this case, that's not what's happening at all. We simply observe individuals, superficially, and when we dig deeply, we find out: yeah, that really is how it seems to work--not in the sense of a divine spark, but rather a complex organic mechanism that is adaptive and learns and so on.

If one wants to poetically describe that as "becoming", sure. But the gradual evolution of the Enlightenment view has resulted in not considering individuals as static and inert anyway and certainly not something that fell into our laps at birth!