Neutral jump is fireballs. If he’s always anti-airing, jump at a range where a jump in will hit, but an empty jump will make his AA whiff. Kara-focus dash is an okay tool to use once a game to get through fireballs. If you’re close enough, you can get a jab combo. If you want to match his FB in a FB war, make sure you’re the one to throw them first. If he throws the FB first and you don’t make a jump read, neutral jump if outside footsie range; walk and block if you’re mid-range. You can try step-kicking his FB start-up if you’re at the tip of step-kick range, you may even get a cr.MK to combo on CH. Make sure you’re always trying to push him into the corner, this gives you more movement options.
If he’s sweeping you as a poke, make sure you play around Ken’s stand HK range. If he’s whiff-punishing with sweeps, do one or to rapid crouches. It’s very likely he’s reaction to your quick movements and not an actual move to punish. You can even do a quick crouch and stand light kick if you’re in his sweep range. The crouch is to test his reactions; if he bites, he’ll sweep and the st LK whill make the sweep whiff.
Tick throws are apart of the basic mix-ups. It’s a guess between throw/block/attack. Don’t feel bad about it. Even Evo champions have to take this mix-ups from time to time (this is gonna be a strong threat in SFV). But, you can also mash DP, backdash, or hold jump to escape the throw after he ticks you.
One of the oldest strategies in playing a solid game, since the '90s, is to be aggressive at the start and get a life lead and make them come to you. Yes, Ken shine’s in offense, but getting the life lead forces your opponents to take risks while you sit back and try to punish their advances. If you ever get back in a neutral position, make sure you’re winning. Dodge his fireballs, poke him if he walks towards you, and AA all his jumps.
If you can’t get a life lead, you need a good spacing game with jumps and smart FBs. Like in the first paragraph, bait and punish whiff anti-airs. Make sure you try to negate his fireballs with your own with occasional jumps where he is unsure if he can anti-air an empty jump. He’ll become more hesitant to anti-air, and you will have the advantage of being up close in his face. Your MK is faster and longer, so your footsie tools are stronger than his at this range.
Another thing is to push him into the corner. Many solid players play at longer ranges and are more comfortable backing themselves into a corner than take an offensive risk. When he’s cornered, you need to make him whiff normals and punish him for trying to poke his way out the corner or by jumping out.