What would make you switch music players?

I'm a developer thinking about building a music player for self-hosted libraries. There's no product to sell yet. Your answers decide what gets built, and whether it's worth building at all. 10 questions, about 2 minutes.

1. Which server(s) do you use for music?

Pick all that apply.

2. Roughly how many tracks are in your library?
3. Which devices do you listen on?

Pick all that apply.

4. Which apps do you use today, and on which device?
5. What annoys you most about your current app(s)?
6. Pick up to 3 things that would make you switch.

Up to 3.

7. How much have you paid for music apps in the last 2 years?
8. If one app did everything you picked in question 6 on all your devices, which price would you choose?
9. Would it be a deal-breaker if the app were closed-source?
10. Want early access (free beta) and a launch discount?

Optional. One email when the beta opens. No spam, never shared.