When someone uses the @username are you supposed to get a notification because you don’t. It says you do when you click on the ? next to the @username on someones profile but you only get it appearing under the @mentions. It would be good to get a notification wouldn’t it?
With regards to names, their should just be one username that is used for everything on the front end. The first and Last name is useful in the backend but out on the site just ONE global name is essential in my eyes!