Sounds good. I think Lin's answer to Tenzin is probably going to be the most significant core of this post. IF YOU WOULD LIKE, you can go through the conversation between Xana and Asami about her father. In that time, maybe Lin could also make Tenzin aware that Asami's father had gone missing from prison which may even further solidify this being Amon's doing?

Yes phones exist 

http://avatar.wikia.com/wiki/Telephone