Is it important to know about word stress?
Word stress is important in English, but perhaps less so than in some other languages. The Italian capitano, for example, means 'captain'; but you can put an accent on either of the other three syllables, and get a meaningful word: cápitano, capítano and capitanó are all parts of the verb capitare. I can't think of a four-syllable word in English where you can change the syntax by reassigning stress in that way.
However reassigning stress does have an effect in English, and a more complex one than is the case in Italian. In that example, the vowels remain -a-i-a-o; there are various phonetic changes in the vowel sounds, but the phonemes remain recognizable: /a/ /i/ /a/ /o/. In many English pairs though, like produce (n)/produce (v), changing the stress changes the phonemes: /'prɔdju:s/ (n) as against /prə'dju:s/ (v). And not just the vowel phonemes - refuse (n)/refuse (v) => /'refju:s/ as against /rı'fju:z/; you could even have /'ri:fju:z/ in some rare contexts (replacing the fuse in a plug).
There is also the general point that clear and unambiguous communication requires accurate word stress.
So I'd say it's essential to learn it and essential to practise it.
Anyway, even if they were all related (which they're not) the point about the link between stress and meaning would still be valid.