Fluther owns it. You can’t delete your questions, unless mods sent it to editing, where you can choose “abandon this question”, but that happens on their will.
Fluther ToS do not indicate who owns copyright of questions posted and whether use has right of deletion, pursuant to Article 17 of EU Law “Right of Deletion.”
@vox If you look to the right of your screen you will see Related. There are 4 questions there that address this same question from older times. Perhaps the answers there will clear things up for you.
EU law is inapplicable. Fluther.com operates under US intellectual property law, under which content creators possess all rights that they have not given away. The terms of service—already posted by @chyna—specify exactly which rights you give away. The only thing you hand over to the site are usage rights, not ownership rights.
I’m sure the mods would be willing to delete comment/questions since you have a right to be forgotten. If it was my site I would would also delete your account, just to make sure there was no way you could be held accountable for your typing.