It’s practically impossible to test the difference in people, because crystallized intelligence includes heuristics that affect problem-solving itself. But there is one, because two people with the same knowledge can score differently (e.g. with different thinking speed or effort).

EDIT: Technically crystallized intelligence may be only problem-solving heuristics, not all knowledge. But I don’t see the significance in the difference (e.g. between turning a word problem into a math equation then applying algebra, one of the Wikipedia examples, vs. “turning” the question “what is A?” into a lookup, then “applying” your previously-remembered A’s definition).

- No, it isn’t.

Is it intelligence to attribute this quote to Monty Python, or isn’t it?

Remembering things is traditionally considered a part of intelligence, memory that is. The subject has been discussed for ages. Personally I favor the statistical definition based on the observation that given a range of different intelligence tasks, individuals that succeed in one task generally succeed in other tasks. There is shared variance, a g-factor. Intelligence.

Intelligence is: Domain knowledge, ability to abstract, ability to compose, creative fluidity (idea generation rate), creative originality (new idea novelty), ability to empathize as well as understand and navigate complex social dynamics, metacognitive ability, and much much more

Often the reduction of intelligence to something simpler is "the engineers fallacy" - an engineering mind is so desperate to quantify something numerically, they oversimplify to try and get some scalar value they can maximize; but the cold hard truth is that the over simplification is too basic to encapsulate the important things, which are often not easily quantifiable numerically