Dude, awesome! The characters now appear in both the tags column and the characters custom column. To remove this redundancy, I simply created another custom column for "genre", so now everything looks good there. I have absolutely NO idea what the admins of fimfiction were smoking when they decided to remove the hover-text on the character tags. Madness.
But yeah, the bbcode problem seems tricky. It looks cleaner now, but there's no way to see links because, as you say, all the bbcode is gone. It may be better just to have the bbcode display as normal. I don't mind the missing italics/bolding/colored text, but the links can be important. It looks messy, but at least you can copy paste the link, I suppose. It's unfortunate, and I hope eventually a solution presents itself, but right now, I think the previous way was preferable.
But the character tags are working now! Thank you so much for your time. Really cool of you.
