SS doesn't really need that compensation, if you look at it compared to werewolf. My main argument is that Flq's cp cost needs to be lowered, because she is not a useful as SS or Qotd. I don't see how she can cost more than 7*SS and the same as 8* Qotd.
Heavy poison for her is a seperate suggestion that would only help with completing lvls faster, not allow you to try other maps because her hp would still be to low. A good example would be the weekend mines. Actually lowering the cd to 15 for moderate poison would help a little aswell.
HP may have less value in the arena for sure but that is certainly not true for actual gameplay. Each point of hp is valuable and can make or break your team. Increasing FLQs stats by about 200 in each atk and hp and 50 in recovery would not make a huge difference, and players with a Qotd would likely not have noticed until somebody mentioned it on the forums.
These are all small but worthy "seperate suggestions" for one of many cards who could use a little push, to see the light of day. Im not saying she needs all these buffs, just one of them to give her a little presence.
Btw there are many cards that after evolving their last form takes on a stronger active skill, leader skill, or both.