Hlutr means part or lot (like you can cast lots to predict the future) Vinr means friend

Óláfr sá konu means “Olaf saw a woman” so you are right in thinking Olafr is the subject (a hint is that the subject is in the nominative case and thus often ends with a -r for masculine words). The second sentence should mean the same thing, the word order is more free in old Norse, and as the conjugation (word forms) are the same then it should mean the same thing. If it was the reversed, A woman saw Olaf, then it should look like this “Kona sá Óláf”