Add new e-mails and a Block Button

I was wondering if someone knows how to add more e-mail templates. I would like an e-mail for user has subscribed, user has left a channel comment, user has left a comment on a video and, user has accepted friend request. I can edit the wording if you can make the code. Like have something that says user has subscribed would you like to subscribe back. Also if you can add a Block button so that users can block people. Here is my site http://www.youruploadsite.com/ If you would like to advertise your service for more options feel free to.