Your understanding of the difference is basically correct. The people who talk about 'wanted' as reflecting a Past situation are not familiar with the concept of the Conditional sentence.
If you want to write a book, what kind of book WILL you write?
If you win the game, what WILLyou do with the prize money?
In both these examples, the speaker is thinking of writing or winning as something possible, though not yet settled.
If you WANTED to write a book, what kind of book WOULD you write?
If you WON the game, what WOULD you do with the prize money?
In these examples, the speaker thinks that writing and winning, while still possible, are unlikely to happen.
In both cases, 'wanted' and 'won', while Past in form, are an essential part of the Second Conditional: an unlikely future event.
Third Conditional, which is barely used in the USA even by educated people, refers to Past 'unreal' situations:
If you HAD WANTED to write a book [but you didn't], what kind of book WOULD you HAVE WRITTEN?
If you HAD WON the game [but you didn't], what WOULD you HAVE DONE with the money?
In short, you've correctly understood the basic difference between your own two sentences. The first reflects a possible, even likely, outcome, while the second reflects a possible but UNlikely outcome.