I can see why you are looking into a new software, loading Tutorial - RpNation - BBcode Guide | RpNation is taking 2 minutes for me 
I believe all your custom styles, like newspaper, challenge, sides, can be done with Generic bbcode wrapper for theme components and CSS.
And lots of it are built-in in Discourse, like code highlight, super/sub script, center block, tables, blockquotes, inline spoilers, dividers, headers, media embed, etc.