Cool that you are interested in WP. I am interested, too but the one thing that worries me every time that I think of making the switch to WP are the Apps..
To answer a quick ? about emoji.. you can still see most of them. My friend has WP and emojis work.
You said that you are a Spotify and Beats music subscriber? I wish the options were better on WP but I am sorry to say that the Spotify App has not been updated in months and doesn't work well at all. Also, Beats music hasn't gotten the best reviews in the App Store.
Spotify | Windows Phone Apps+Games Store (United States) - July 12, 2013 last update
Beats Music | Windows Phone Apps+Games Store (United States) - ratings aren't the best
The quality of apps really needs to be better on Windows Phone. It makes me upset that most things in the app store are mediocre. The official apps might "be" in the app store but that does not mean they are good and have the features people want.
Good luck on your decision. I'm hoping the app situation gets much better and companies will actually care about the apps they make for WP. Sorry for the rant... I think I'm just upset that WP is so behind and people don't seem to care about it. I like the UI and would like to try out a WP and MSFT but the apps are holding me back... Also 8.1 is coming out soon I think that should improve a lot of things!! Maybe finally make WP a little more visible and attractive.