Just switched (finally) from iOS to Android... here's what confuses me

I've been an iOS user since 1.0 and after running iOS7 for some time I decided I needed to try something else. So far I'm fairly satisfied with my HTC One but there are a couple of things that I haven't been able to understand that maybe you can help me with.

1. Battery - Even my "old" iPhone5 lasts two days on one charge whereas my HTC only lasts for 12-14 hrs... What can I do to extend my battery life?

2. Airplay. I've seen apps that can stream local music to Airplay enabled speakers but does this in any way work with Spotify or Rdio? What about streaming video to AppleTV

3. Bluetooth - In my car I listen to Rdio/Spotify a lot and when streaming from my iPhone to my car's media system I would get artist name, album, song etc appear in the title of the car's system, where as with my HTC I don't get anything (except the music obviously). Is this because of the app or the hardware? Is there a way to get it?

4. Emoji - is there no way of getting the same emoji pack in the messages app as there is on iPhone? All of my friends have iPhones and use emoji's heavily so would be nice to keep sending them back :)

5. Launchers - people are often amazed by launchers and express the amazing functionality of them but I can't seem to see what's so great? Is it because Sense is decent or is there something I'm missing?

Thanks for any assistance on the above!