I guess, I'm a partial nihilist then, because there surely is no objective value and meaning nowhere to be found :D However, nihilism as such is rather incoherent as it renders itself moot when followed through to its logical conclusion. I would also argue that it's not true that knowledge and communication are impossible. We obviously know (does not matter if what we know is illusion or not) and we obviously communicate even though we can debate about how much of what aspect of our knowledge is communicable (furthermore, it's not only humans who communicate -- information is exchanged even on "inhuman" and "impersonal" levels and scales).

I would also say that when you say that "we can only feign at adopting such an all-encompassing perspective" because "nihilist is a human mammal imagining what it’s like to be nothing" you ignore the fact that we can directly experience nothingness. It's what happens when you oscillate between downstate and upstate in deep sleep. These states can be also accessed intentionally. Either through meditation (see Buddhism and eighth jhāna of either perception nor non-perception), or through various practices of lucid dreaming, but also by overdosing on nonlethal psychedelics (particularly hemp). But yes, for all practical purposes such state is no different from being dead (see all those non-stop "blissed out" and absent minded sadhus) and hardly suitable for living as a permanent state of mind.

However, such experience may trigger a wider realization in terms of nature of consciousness, that is, our identity or personhood. And that's what makes the whole difference in the world, even though that knowledge in itself changes nothing. The reason that it's so is that mere intellectual familiarity (which you describe) always requires faith and that seldom translates into action, while knowledge entails action by default.