I do not understand what you mean? Want to preview posts when posting? I'm afraid that there is no such mode for you. Lol
Sometimes, you should try to read other member's reply, not just the title and the OP's thread. mdayonliner already explained what OP means and it is just above your reply. Let me quote it for you 
What I understand is, you mean an edit history visible to public. At the moment I guess only mod/admin can see edit history, not sure though. Publicly it's not available however I think it should be publicly available too.
I experienced the need for this when I had a hard time (I am still suffering) going on with a member. He kept changing his previous posts (without keeping reference most of the time) where he could easily correct his contents on the new comments. Editing older posts (which already responded based on your previous content) without reference actually can change the whole point of view of a conversation. It's mislead the new readers and they actually find it hard to get connection of the conversations.
I experienced the need for this when I had a hard time (I am still suffering) going on with a member. He kept changing his previous posts (without keeping reference most of the time) where he could easily correct his contents on the new comments. Editing older posts (which already responded based on your previous content) without reference actually can change the whole point of view of a conversation. It's mislead the new readers and they actually find it hard to get connection of the conversations.
You can't check if the post is edited or not via a Mobile browser.
Not true. You can still see if it's edited or not. The dotted line is still visible in mobile browser (Google Chrome) but not sure in other browsers. But i guess it's all the same.Example.
