I love your take. It would be glorious. Classic dying gambit from Lex: "Even if I die, you lose everything and everyone you ever valued, and I win, all because you did and reacted exactly as I knew you would."
You're not wrong, though Kara had no hint of romance whatsoever in Season 4, as far as I recall from seeing the episodes. It was all about that good sisterly love and female friendship, which wasn't so bad, by any means.