1. Samsung S8+ Exynos (SM-G955FD)
2. 7.0 OTA (G955FXXU1AQDD / G955FOXM1AQDD / G955FXXU1AQDD)
3. I'm sure it does, it's in the specs. And It works with HI-Res BT Player App, for example.
PS. Need it to work for my Bowers&Wilkins P7 Wireless headset, it does work with my old Note 4 Exynos.
UPD: alfa-704 solved my problem!