What are you talking about? Editing an Overview and checking the results is about the easiest thing in mission editing. Put the mission folder in your Missions Directory, edit the file, alt-tab into OFP and click on the mission in the Main Menu.
I don't know of a "new page" tag, although you're right it would be useful.
I confess I'm slightly gobsmacked by the absurdity of asking "how many <br>s" without telling us how much text you've already written. ;D ;D ;D