No you can't, the noun has to be seperated ( and there is a surplus e) Nederlandstalig volk.
However if you meant adress the Dutch speaking people you wouldnt used that (it is more like a Dutch speaking people (tribe))
I guess you could use
But noone would actually use that or Nederlandstaligen.
I guess either mensen die nederlands spreken ór just keeping it simple Nederlanders (that would however exclude people from Belgium the Dutch antilles and suriname. But when the rest of your text is about language people will understand what you mean and even if they are not from the Netherlands might reply)
And yes enige.
Yes, if you want to write een as one in this sentence you'd use één. This is what Wiktionary says about this:
When it is unclear from the context whether een is the number or the indefinite article, the former is written with acute accents: één. In all other cases it is written without. For example, een van die is 'one of those'. But een appel can mean both 'one apple' and 'an apple', so if the former is intended you would write één appel.
Is it correct that in negative and/or singular cases, "enkel" means "single" (e.g "Geen enkel kind hoort het schaap", "een enkel bord"), and in plurals it becomes "enkele" and means "a few"?
What if it's not followed by a het word? For example, should it be "een enkel hond" or "een enkele hond"?
Geen= niet een (None= not one/not a) so you could think of both of them as an indefinite article.
It should be een enkele hond.
Een enkele hond=A single dog
De enkele honden=the few dogs
Enkele honden=several dogs.
Een enkel schaap= A single sheep
De enkele schapen=the few sheep
Enkele schapen=several sheep.
Enkel basicly means single (both from 1+ (ŋ)kəl) and enkele several single