I need some help before switching to Windows Phone 8

A few months ago, I wrote about how I don't want a 4+-inch phone (link). I currently use a Desire S and the size is perfect for me. But the thing is, I want something new. I started looking in phone stores, but my eyes were always drawn to one phone: the 8X. I played with it a few times and I just fell in love. I don't even care about the big form factor anymore. I have, however, a concern. The apps. That's where I need some help. I don't play games on my phone. I have an iPod Touch for that. I do, however, have apps that I use on a daily basis that I want to continue using after switching.

  • Gmail. How is gmail integration on Windows Phone? I don't care about labels. I just want push mail and threaded messages.
  • Google reader. I read a lot of news outlets and it is easier to view those in Google reader. So are there any good Google reader apps?
  • Instapaper. Is there an Instapaper client on Windows Phone or are there any good alternatives?
  • Public Transport via Google Maps. I live in The Netherlands and I use Google Maps to see when the bus or subway arrives. Is there a Google Maps client or alternative? Or is Bing Maps capable of offering transit directions in my country?
  • What's app. How is What's app for Windows Phone?
  • YouTube. Are there any good YouTube apps on Windows Phone?
  • Shazam. Not a very important app, but still fun to have.

I'm definitely buying a 8X if these are covered.