You don't paste anything. Open web connect. When it opens your Google account should appear. Select it. A box will open to put a Nick name. Create one. Once done it should say you are now able to download Roms to your phone. Go to download rom and select it. When it opens you will see aosp.
I don't think so. I'm using xionia now since our phones are not offically supported by rom manager. Not worth wasting the extra space on my phone for a program that half works so untill our phone is supported I'm using xionia with bumblebee.