Gabriel...Mr Peachey nailed it. He is right about both of your questions. It is not a mere 'stylistic choice'

OK, this might explain my answer on an earlier question. You use "the" with nouns (obviously). When you have a superlative which describes a noun (superlative adjective), you must add "the". If the superlative describes a verb (superlative adverb), then you cannot use "the". There's no reason to do so. In your example, "most" describes a verb.

You can use both, including or excluding it is a stylistic choice :)