Sentence Correction

Hi:

Can someone please help me out with the following:

1) When can 'none' be plural?
2) Much Vs. Many: Is the usage of 'much' restricted to uncountable items and that of 'many' restricted to countable ones? (I mean do they mirror the usage of 'less 'and 'few' respectively?)
3) In one of the flashcards I came across the following:

Although about 99% of the more than 50million Turks are Muslims…
Although about 99% of more than 50million
If we use ‘the’ we are saying that there are only 50million Turks in the whole world; if we don’t use ‘the’ we’re saying that there are possibly more than 50million Turks in the world

I really dont understand how 'the more than...' refers to only 50 million when we clearly have '...more than...' in the sentence.