Можно сказать "много ЧЕЛОВЕК"?
Nope, человек is a counting form used with numbers. Много and мало are not considered good enough to justify that use, though несколько (several) and сколько (how many?) are.
The word люди (plural of человек) is used when the number of people is uncountable. For countable number of people, including "несколько" (several, few), use человек: