It sounds like you're saying that pure nihilism is actually impossible, as there are always competing desires and motivations at play within. So, one can never truly abandon moral principles when making a decision. Maybe the most one could be is a "casual nihilist" - one who sets themselves against the norms and values of culture and society, putting them fiercely at odds with others. Yet, they still follow their own principles and values as it is impossible to live a value-less life.

I think of the writer of Ecclesiastes who can repeat over and over again, "Meaningless! Meaningless! Everything is meaningless!" (a nihilistic or deconstructionist perspective) yet the writer then spends a large amount of time seeking out that which is meaningful. In other words, the search for meaning and truth is itself a value, and the author considers this pursuit meaningful. (Thus, they have undermined their own nihilism.)

I still need to think on this more as it relates to death. But good thoughts here!