I find the Michel Thomas audiobooks very useful for learning Spanish/french/romance languages.
Can't speak properly yet, but can listen a little and read a lot. He explains a lot of the patterns that are common to romance languages, and makes it easier to understand the next romance language
As to what language to pick? Agree with OP's list/ranking , though some languages are usually harder to learn (Chinese/Japanese harder)
Your locality also matters, makes a lot of sense to Learn Spanish first in USA, or french/German first in some parts of Europe