Is it acceptable to leave an extra space before punctuation marks in English writing? If so, in what cases is it appropriate? If not, why is it not recommended?

Not nowadays for most punctuation. I’ve seen it in some very old texts, but it hasn’t been correct for about 200 years.

The exceptions are the ellipsis, the dot-dot-dot character, and the endash, when they are used to indicate a brief pause in an on-flowing sentence.

For example, in Harry Potter the famous prophecy goes 'The one with the power to vanquish the Dark Lord approaches ... born to those who have thrice defied him, born as the seventh month dies ... and the Dark Lord will mark him as his equal, but he will have power the Dark Lord knows not ... and either must die at the hand of the other for neither can live while the other survives ... the one with the power to vanquish the Dark Lord will be born as the seventh month dies ...'

The final one is debatable. Often, if the ellipsis represents a trailing-off of voice or an incomplete end to a statement, you write it without a space – “as the seventh month dies…” – and if it’s definitely the end of a sentence with nothing to follow, it should really be written with four dots, the final one representing a full-stop to indicate the end. You can also end a trailing-of interrogative sentence with the dots and a question-mark, e.g. “I wondered if you…?”

Note the use of endashes in the above paragraph. Endashes, slightly longer than a hyphen, are often used like brackets to delineate a side comment which could be cut out of a sentence without greatly changing its meaning. When they are used in that way they have a space either side of them, but not when they are used to indicate a from/to pair like “Club 18–30”. Meanwhile the even longer emdash is used, at least in modern British English, where a word has been interrup— and does not have a space before it, but American usage, and British usage before about 1960, may vary.