What arXiv CC licenses are compatible with American Physical Society publishing? I'm having some trouble understanding exactly what the American Physical Society (APS) transfer of copyright agreement does and does not permit, and I was wondering whether someone here may have a clearer insight or previous contact with them to know exactly what their position is. Their copyright FAQ is, I feel, not clear enough on the subject, and it's not quite clear how I should contact them about this.

The relevant paragraphs from the copyright transfer agreement are, I think


  2. The nonexclusive right, after publication by APS, to give permission to third parties to republish print versions of the Article or a translation thereof, or excerpts therefrom, without obtaining permission from APS, provided the APS-prepared version is not used for this purpose, the Article is not republished in another journal, and the third party does not charge a fee. If the APS version is used, or the third party republishes in a publication or product charging a fee for use, permission from APS must be obtained.


and 


  4. The right to post and update the Article on free-access e-print servers as long as files prepared and/or formatted by APS or its vendors are not used for that purpose. Any such posting made or updated after acceptance of the Article for publication shall include a link to the online abstract in the APS journal or to the entry page of the journal. If the author wishes the APS-prepared version to be used for an online posting other than on the author(s)’ or employer’s website, APS permission is required; if permission is granted, APS will provide the Article as it was published in the journal, and use will be subject to APS terms and conditions.


The latter one looks pretty inclusive, but it does not specify whether all licensing schemes for e-print servers are acceptable or not. Similarly, in their  I am worried, in particular, by a note in the arXiv license help page:


  The Creative Commons Attribution license in particular, permits commercial reuse and thus conflicts with many journal agreements.


In particular, posting to an e-print server may be construed as overstepping the rights granted by point 2 of the agreement, since it can be used by a third party as permission to republish it in print and charge a fee for it. If that is the only objection, then choosing a CC Noncommercial-ShareAlike license would be compatible with the above.

I have two specific questions about this.


Is my reading of these publicly available documents correct? Did I miss important information either on these or other publicly available resources?
Does anyone have specific experience with them regarding this question? Is there some specific contact for these matters?


(I believe the non-exclusive license to distribute, which is the most restrictive arXiv license, is definitely compatible. This question is mostly about the Creative Commons licenses.)
I don't think you can use any CC license with such a publishing agreement. 

Point 4 allows you to post the article to preprint servers. This covers the non-exclusive distribution license that Mangara mentioned in a comment: You permit arxiv.org to reproduce the article on their website. Importantly, you don't grant any rights to anybody else with this license.

If you put your article under a CC license, you would grant anybody the right to reproduce it (under conditions depending on the exact type of the license). Whether it is published on arxiv.org or not doesn't really matter here – arxiv.org will just be one of the potentially many users of this license. Looking at the arxiv help page, this is hidden behind the specific wording they use. For the non-exclusive distribution license:


  grant arXiv.org a non-exclusive and irrevocable license to distribute the article


which makes it clear that you are giving permission to arxiv.org and not anybody else.

For the CC license, they say instead:


  certify that the work is available under either the Creative Commons Attribution license, or the Creative Commons Attribution-Noncommercial-ShareAlike license


that is, you don't give a license to arxiv.org specifically, but to the general public, and arxiv.org is just going to make use of that general license.

I don't think your publishing agreement allows you to issue a CC license, even the noncommercial one. The publisher does not allow you to grant a license to anybody, just specifically to "free-access e-print servers".