ok here are my thoughts.
magic build is the most common build for ninjas. but like magic classes, it gets so fucked up with gtb that I just won't use this build unless I know I am against guys who aren't fast enough to switch to gtb. That is why I would rather use a ninja-skilled staker than a ninja. The problem is that gtb will never be nerfed because people here would QQ more against it. My only suggestion against this is make the dragoon warlord card ENABLE you to use Level 1 strip shield for magic classes, not just make it a 5% chance while attacking. Because to be honest, I love it when magic classes goes near my sinx or champ and tries to strip me by attacking.
throw fuuma shuriken is not bad, but not that good either, considering that it does less damage than TSS(with the same cards) and yet, it can be used with a 2 handed weapon. either buff the damage of throw fuuma shuriken or make a one handed weapon for ninjas that could use throw fuuma shuriken.
Final Strike is good if you build it right, but again, it is a weaker version of asura(so weak), a ranged skill(defender and pnuema can block it) and not good when fighting in groups(it reduces your hp to 1, so after you strike, probably you will die.
So in essence, this is on what I will agree.
1. Either make throw fuuma shuriken stronger that it can go par with a good TSS WITHOUT using thana or make a one handed weapon for ninjas.
2. Make the dragoon warlord enable strip shield level 1.
3. A little HP boost would do, but not as high as the given hp boost of tao to mage classes, since ninjas have more survivability even with a few hp.
4. No on removing the delay on cicada(3 kiels kills the delay anyway, you can even live with 2 kiels)
5. hopefully, like what Jay suggested before, make f cloak remove catalyst requirements of ninja skills.