If I add an 文章 to a club, then unsubscribe from that club, will my 文章 be deleted?

No, your 文章 will stay on that club, even if 你 unsubscribe from that club. Even if 你 were to 删除 your 潮流粉丝俱乐部 account (no idea why 你 would want to do that though), your 文章 will stay there for everyone to see. The only one able to 删除 your article, is either 你 或者 an admin.

Hope I could have been of help. ;-)

No, I don't think it will. However, I'm not totally sure.

Last time i checked no i dont think it will but 你 will not get a medal in that club i Tested it out once well If 你 "unsubscribe" from the club your most likely lose the medal progress so no it wont get Deleted