The English in the original post is fine, considering that the sentence quoted is from a program about the Tudors. I don't exactly picture Henry VIII saying 'If you want my advice.'
The examples in #1 are better for modern English (except for 'I should,' which is not present-day except in very formal BE), but historically 'would' is comparable to 'wollte' in both subjunctive and past senses, so you can see the relation.
There are quite a few discussions on this question in the forum archive (Suche in allen Foren), it's just that unfortunately they're hard to find because the search algorithm ignores short words like 'if,' and 'would' alone is too common. Here's one that has some quotes missing because of angle brackets and HTML, but also still has some longer discussion:related discussion: If-Sätze
There are several others, which if I come across them I'll try to bookmark, as this is probably one of the top ten topics that would appear in a content FAQ if we ever had one. There's also a thread somewhere on the 'I should' vs. 'I would' issue; someone else undoubtedly has it bookmarked, or maybe I'll remember it.