Actually the obscure stuff being uploaded usually gets downloaded pretty fast; atleast within a day or two. Anytime I've uploaded something fairly obscure, it hasn't taken long for someone to get it.
Ratio really isn't all that had to keep up. You just have to leave torrents seeding, and that's not so bad.
As for getting punished for downloading obscure stuff, you'd be surprised. If you're seeding a torrent with a low amount of seeders (2~3), you're more likely to connect to seed to someone. Which, in turn, raises your ratio.