@Psycho_Mantis sorry that you caught TYM on one of its less helpful days. I'll try to answer the questions in your OP as well as give you feedback on the video you posted:
Against any character, you need to understand their game plan. With Hellfire Scorpion, his game plan is to get you to jump, which is why you're eating d2s, spears, and teleports – you're doing exactly what he wants you to do. Understand that you're defensively at your weakest when you jump; you're usually at massive frame disadvantage vs. a grounded opponent and you're also physically unable to block. As Kung Jin, you might be able to get away with jumping into instant divekick *sometimes*, but scorpion's jumpkick has such massive priority that it's really not worth the risk. Ideally what your approach should be is to jump only when Scorpion goes for hellfire and stay grounded at all other times so you can block. Obviously that's not really humanly possible, so your next best bet is to do a cost-benefit analysis: out of all of my options, which option gives Scorpion the least gain in a best-case scenario for him? The answer is usually to eat the hellfire and stay grounded since hellfire doesn't lead to a potential combo.
That brings me to my approach against scrubby Scorpion players. Against really scrubby Scorpion players, I usually just sit there and block. Walk in patiently and let them hang themselves. Sure, you'll eat hellfires here and there, but someone that's truly bad will get antsy quickly. If he goes for either spear or teleport, you get a free combo. You *must* learn to punish both of these options effectively. Even Scorpion's EX teleport is punishable, so don't be thrown off by the differing animation. The only thing to look out for with the teleport is the cancel; it requires 2 bars of stamina so it's not something that can be abused easily, but it *is* still an option to respect.
Anyway, once you're in range for any of your armored moves, that's when Scorpion has to play your game. d2 and spear won't save him, and trying to teleport out just means that you get to take damage for even less work.
Video feedback: beware of and try to prevent yourself from going into auto pilot. I noticed that you don't really play as if you're anticipating Erron Black's next move; you instead seem to do what probably gets you results the majority of the time. The Erron player was able to beat your jumps almost every time and was even able to anticipate your wake-up pressure and punish it, which tells me that you need to spend less time attacking and more time thinking about your opponent's next move. It's really hard to do online, but it is possible with practice. Kung Jin also has really great range on his normals, so you don't need to be so close to the opponent to mount an attack. Try working on your spacing a bit to give yourself positional advantages, and definitely try to play more patiently and let each match develop a bit.
Hope this helps!
