What your proposal does is to repeat the mistake that was made with Occurrence (well I consider it a mistake for a fully normalized model). You want to take metadata terms that apply in one particular subset of cases (the terms that describe the physical aspects of the individual and its pieces) and combine them with terms that apply to a more general situation (the terms that describe the role that Individual plays as a node connecting multiple Occurrences to Identifications or as a joining table in a database). This sounds good to you because you mostly deal with the physical aspects of individuals and their pieces but some people (photographers and people who make observations) don't need to describe the physical aspect because they don't collect them.
I disagree with this assesment. Forgeting which terms apply to Occurrences vs Individuals (that is much less important to me), the real issue here is the logical limit of what an "Individual" is.
We both agree that an Individual consists of actual biological stuff. Physical stuff. Cells with biomolecules within them. A digital image has no such stuff. A film image has no such stuff.
We also both agree that an Individual can have one to many Occurrences assoiciated with it. One Occurrence will usually be the case if the entire organism or population was extracted from the natural habitat the first time that it was documented to exist, and placed in a Museum or zoo. There may very well be more than one Occurrence linked to an Individual that is not extracted from the natural habitat, and is revisited over time (and either left alone, or eventually extracted entirely, thereby representing the last meaningful Occurrence for that Individual).
We also both agree that an Individual may have more than one competing or reinforcing Identification associated with it, but it cannot have more than one concurrently legitimate Identification associated with it.
We also both agree that Individuals can be derived from other Individuals.
As far as I can tell, the only real difference we have (forget about the tokens for now) is that you want the chain od derived Individuals to stop at the level of WholeOrganism; whereas I would like to allow the scope of "Individual" instances to extend down to a Part of an Individual.
We can argue about the properties and tokens later; first we need to nail down the "essence" of an Individual.
My greatest concern about your scoping of "Individual" is that there are non-trivial numbers of examples that straddle the "WholeOrganism" threshold. Sponges, corals, certain fungi, budding organism, clonal organisms, and a whole bunch of other examples make it unclear where the "Individual" (sensu you) ends, and the "part" or "token" begins.
My apples/orange analogy would be better if I'd said that you are talking about apples and I'm talking about trees.
No, I'm talking about Apples *and* trees. An Individual "WholeOrganism" Tree is derived from another Individual "Population" of the same species of tree. In the same way, an Individual "OrganismPart" apple id derived from an Individual "WholeOrganism" Tree. Each of these (Population of Trees, WholeOrganism Tree, Part of Tree) represents, in my mind, a potential Individual.
Aloha, Rich