Let's get rid of the garden path, shall we? I'd like to revise your examples, in a way that leaves your question intact:
(1) This is the city whose map I have seen.
(2) This is the city that I have seen a map of.
Both sentences are grammatical, but they don't have the same meaning. Here are paraphrases of the relative clauses:
(a) I have seen the city's map. ( = I have seen the map of the city.)
(b) I have seen a map of the city.
Just as (a) supposes that there is only one map of the city, (1) also supposes that there is only one map of the city. But (b) does not make that supposition. The speaker has seen one map of the city, one among many possible maps of the city.
I wouldn't worry so much about "pure possession" versus "mere association." That isn't the key to choosing between the
whose-construction and the
of-variant. Definiteness versus indefiniteness does play a role in the choice, at least sometimes, as (1) and (2) above illustrate. In philosophy, it is common to find sentences like this:
". . . if we have no knowledge of anything which does not resemble our ideas or sensations, it follows that we have no knowledge of anything whose existence is independent of our perceptions" (source).
Now, does a chair possess its existence? That would be a pretty odd thing to say! Yet there is nothing at all wrong with the construction I just quoted, unless you, as an English language learner and native Russian speaker, want to dismiss an entire genre of native writing and thought in English as grammatically improper. "Anything whose existence" means "anything the existence of which." It's that simple.