I will do my best to respond soon.
For tonight (it's 01.00 here) I'll just try to dispose of one comparatively minor point.
This is an unfortunate choice of labels, which I'd prefer not to go into in this thread. Some writers use 'determiner' for the name of a word class and 'modifier' for a function. Others use 'determinative' for a word class and 'determiner' for a function. We'll have less potential for confusion if we don't spend time on the determiner/determinative' words.I think up until now I've been considering word class as a classification of form. So that 'determiner' is a word class but 'determinative' and 'modifier', since they relate only to function, are not.