I thank you sincerely for demolishing my examples. A few follow-ups.
"me voy a casar con una mujer que tiene mucho dinero"
Given a situation where the speaker is identifying more than one woman, I could accept "mujer que tiene mucho dinero" -- less "una" -- to be a collective reference, and as specific as we might consider such a reference to be. I'm thinking how I might represent that in lojban with "una" in the outer quantifier:
{pa le ricfu ninmu}
But then I wonder: What would it look like without a given number?
"me voy a casar con las mujeres que tiene mucho dinero"
Setting aside the issue of whether these marriages are intended concurrently or consecutively, how distinct must the enumeration of brides be in order for the sentence to be correct? Does that question make any sense? I don't actually expect a natural language to have a clear policy. But I think it's fair to ask where lojban comes down on such things. To the point, what would the standard of specific reference be for this statement?
{mi ba speni le ricfu ninmu}
Is the answer different if we add an inner quantifier that describes a large and/or vague quantity?
{mi ba speni le so'i ricfu ninmu}
How does one refer specifically to an imprecise number of individuals? Does this touch upon the "levels of specificity" you suggested? Can {le} as presently defined ("refers specifically to an individual or individuals that the speaker has in mind") tolerate continuous, or even graded, levels of specificity? Is there any supposed limit to the number of individuals that can be held in mind at once? And can {le} only be used with countables?
mi'e la mukti mu'o