And, good god, not Discourse, of all the crappy softwares.
That looses the way a forum works completetely. There are better software available that can keep the look and feel, and still offer all the things you list.
But i would not get my hopes up, there was a recent discussion about fixing the attachement system. I mentioned XenForo, but that suggestion was not well received
Even though XenForo can keep the classic forum look and feel. And it even works great on mobile, without needing any superfluous apps.