Yeah that wouldn't be fun. I hear about Swain top sometimes, and I've tried it once or twice, but I never really see it. His inability to push/no escapes early can be abused if they're smart. I've also tried Diana jungle a bunch of times since her release, but I've never felt worthwhile at it. Her ganks are strong at 6 and above, but usually I make an impact before that time with other junglers.
When I play her top I like building Glacial Shroud as my first item (if i'm against an AD champ). Every stat is so useful. Upgrade it to FH or Iceborn later, both are amazing on her. Core is usually one of those items plus Zhonya and Abyssal, really tanky yet still do a lot of damage. I've been able to 1v1 adcs with full tank builds. I know Riot said something about reworking her to be more of a fighter and less of an assassin, but that was weeks/months ago and no word since then, I wonder what's happening about that.