Syntax are important in a piece of writing because it is essential for written communication.
Without syntax, the sentences are harder to understand.
Example: Incorrect: While watching a movie, people who text on their phone are very annoying
Correct: People who text on their phone while watching a movie are very annoying.
It just makes the sentence easier to understand.
Hope that helps!
Hypothesis is a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation. Theory is a contemplative and rational type of abstract generalizing thinking or the result of such thinking. Apparently, if the hypothesis is proven it would become a theory.