A:AnswerThe blue tooth will play out of any compatible device, as for the ear buds not sure if you can use 2 separate but if your have a pair that are for one set and they are wireless, it should work
A:AnswerTo play Spotify music on other devices without data connection, you can download Spotify songs with AudFree Spotify music converter for Windows. This is a professional software allows you to download Spotify playlists to MP3, then you're able to listen to them on any device freely. For more: https://www.audfree.com/spotify-music-converter-win/
A:AnswerI can't tell you how long it goes before it dies but I can tell ya I just got back from a 5-hour motorcycle ride and it was on the entire time. The battery indicator still shows prolly 90%+ full
A:Answer1. I'm unsure because I do not use the radio feature on there
2. Yes there isn no special jack, however, it will have to connect via bluetooth in order to protect the device
3. No