I have some answers to a couple of your questions.

1) To tag, use the @ symbol followed by the username from the writer. Then click on their name coming up. For example to tag me = @j-edmunds.

2) To send a private message to a writer highlight any part of their post. Click the last option a white envelope with a lock in it. You can send a private message to the person now,

3) I don't know the answer. Sorry

4) To access your drafts from your profile page. Click your photo or avatar. Choose stories (second from the top. Your stories list will appear drafts as well as published stories.