Didn't see the response to this until today,
So first, God never commended anybody for having multiple wives in fact His express command in Deuteronomy 17 was that a king should not multiply wives to himself. So anybody with more than a wife was not in alignment to God. The fact Solomon's wives led him astray was precisely what God warned about in multiplying wives. The wives would turn their heart away from him, so the effect of Solomon's heart turning away was the result of his disobedience in having many wives. As God warned.
In any case, old testament saints as great as some of them are, are not our examples, Christ is and His teaching on marriage and sexuality is that from the beginning it ought to be one man one wife.
God created sexuality, yes, but also teaches us the original design and framework for its enjoyment. Marriage between a man and a woman. God never tells men to go crazy and bang as many chicks as they want to. So God and Paul are on the same page in that respect. Paul himself talks of sex as a good thing between a man and his wife in 1 Corinthians 7.
On our nature. Our nature is evil naturally speaking. The bulk of our instinct is in the direction of rebellion against God. So the way we are is not necessarily the way we should be, otherwise a psychopath or a person attracted to minors for instance should be given free reign to express their true nature much like people who feel their nature is to have forms of sex outside the boundaries of scripture.
Wishing you all the best on your journey.