Well done. Your story banner certainly makes me want to read your story. (Whether I'll have time to do so once it is posted is another story altogether.)
I agree wholeheartedly that comic-book Clark treated Kara very shabbily. Not only did he put her in an orphanage, he also kept her as his "secret weapon" way too long. I could see him telling her not to use her powers for a short time after she came to earth so that she could first get the lay of the land, so to speak. But having him tell her not to use her powers just so that she could be his secret backup was definitely not something L&C's Clark would ever do. (If he tried it, Martha would manage to tan his invulnerable hide.) Then again, Silver Age Superman was a bit of a jerk; he often made his friends miserable while he tried to teach them a lesson.
On the positive side for Silver Age Kara, however, is that Superman did eventually let her become Supergirl and use her powers openly (Action Comics #285). Also, she was eventually adopted by Fred and Edna Danvers (Action Comics #279).
Joy,
Lynn
