No, I don’t think so. If you insist on telling the user that Qubes is free of charge, then you could use free and libre in “FLOSS” for that; I see no problem with that. However, AFAIK it wasn’t the intention. It’s just a consequence of the wrong term “free”, so it has to be explained. But why is the lack of payment so important anyway? If you say that, you will get a reply that “Qubes is only free if you don’t value your time”, which is not really wrong: It’s a steep curve to start using Qubes.
Again, it looks like an explanation of the ambiguous word “free”.
I agree. But providing a link is important, e.g., to Wikipedia. Answering the frequent question about Qubes is also important.
Of course it is. See how Debian implements it. Qubes should do it too, as evidenced by all the discussions I linked. Users want Qubes to list nonfree packages, so they can be easily identified and removed if possible. On my laptop, I do not need any proprietary packages at all (not even microcode: it’s in Pureboot), but it’s not easy to remove them all in Qubes.
We can start from a good documentation of the problem, as I explained above. Qubes has been too silent about it, as discussed in this topic. An Issue in PureOS about Firefox brings attention to the problem, as it should. It has never been an easy problem to solve. And too few people know about it.
It’s not deprecated. I have it on my Librem 5 and it receives regular updates. See this, which is still relevant AFAIK.
Most of the Qubes FAQ isn’t necessary to get started with Qubes, if not all of it. It doesn’t make it useless or unnecessary.