Pre-Sale advice sought: Bluesound speakers and Roon Nucleus

No, this is complete rubbish.

No.

Yes.

Note that if you’re going with Roon rather than BlueOS there’s a myriad of other potential options as alternatives to the Bluesound speakers. If you’re sticking Bluesound though, I would advise waiting until the current Bluesound sync bug is addressed (search the forum) - it has taken over a year but finally looks like it might happen.