I think your post needs some clarification.
> After a while, space itself would expand meaning that the ruler will now be longer than what it was.
The expansion of space must be measured with respect to something. The usual idea is that space is expanding with respect to other properties of the physical world, e.g., the mean distance between electron and proton in a hydrogen atom. So, because your hypothetical ruler is made of atoms, the claim is that tomorrow it will take more of those rulers laid end to end to reach distant galaxies.
In contrast, one kind of "ruler" that _is_ changing when space expands is the wavelength of photons and other ultrarelativistic particles. If space expands by 1%, photon wavelengths increase by 1% (as measured w.r.t. your hypothetical 1 meter ruler made of ordinary material) and thus photon energies decrease by 1%. This change is the explanation for the redshift of light from distant galaxies.
> After a while, the space between the nucleus and electrons or within the nucleus itself will become too large, ultimately ripping apart for the fabric of reality itself.
I suspect you are referring to cosmological models that end with a "Big Rip". In these models, the amount of dark energy in a constant volume of space (as measured with an ordinary ruler) increases with time. Eventually, the density of dark energy becomes greater than the density of other kinds of energy, e.g., the binding energy of atoms. Then fluctuations in this dark energy will rip apart atoms.
Because the properties of dark energy are hard to measure, it is not yet clear how its density changes with time. The current so-called "standard model" of cosmology, Lambda-CDM, takes the density of dark energy as constant, and this assumption is consistent with our best current measurements. So, as far as we can now tell, we are not living in a "Big Rip" universe.