Caveat for all of this. I haven't played much against MadKing, ratxt1, or deluks. I've had good success against Geigers with Oni, and more recently with Troq in the match-up though, and that's the place my advice comes from. Take it with a "this is speaking from personal experience, not from theory" sized grain of salt. Maybe my opponents primarily mind-gamed themselves to death. I don't know.
I was primarily referring to lategame TD set-ups. Do you play these too risky (dominant throw too much) or too safe (reversal with Joker so you will only take 20/21 damage on a combat loss)? But the early game has its same share of tension. In the early game, where Geiger is primarily playing spiral/block/normal against grappler types, are you dying because you're playing too risky (trying to throw his blocks too often), or too scared (blocking too much/spending too many reversals)?
Ah, okay. Keep in mind that your throws only need to fear Qs. And if you're a high health character, you don't even really need to fear those in the extremely early game. Throwing into a J is as effective against Geiger as it is against Grave (very).
The other thing to keep in mind with high health characters is that Geiger's spirals beat blocks at the expense of his early game. If you take ten damage and then reversal into a block, you're back at square one and you haven't wagered much of significant value.
Lategame, sure. Early game (again, against high health characters), AA is proooobably a loss you're okay with taking, and K, so long as you don't get mixed up for significant damage on the subsequent turn, can also be shrugged off.
Thinking purely in terms of "block-block favours Geiger" is also going to lead to more pressure than it warrants. Block-block favours whoever needs tools more, and whoever draws the more useful tool off that turn. If you're Troq, block-block is actually pretty damn good: you avoided a large normal string, you got a hand that better accomodates powering up for AAA/AA, you got another chance to draw a crucial dodge or Q.
I suspect this may be the crux of your issue against Geiger. If you are never blocking with confidence, or allowing Geiger to block successfully, this match-up will definitely fray your nerves and cause you nightmares. Geiger is like any character: sometimes he draws garbage hands and doesn't find the tools he needs. If you never find a moment to rest in this match-up, you will spend energy jumping at shadows and overreacting to threats. And Geiger is extremely good at punishing people who throw too much and attack too much. Probably better than punishing people who block too much, to be honest.
Not without cost, risk, and not at all times. Q is a bad reveal in the early game against high health characters if it beats and attack or throw. QK is okay. Q567 is maybe okay, even with the big damage it provides. Both of those lose to every character's 2 poke. Both of those are mostly fine to block. Both of those cost Geiger cards in the early game he is trying to escape from.
I think the best characters against Geiger are those that disrupt both his early and late game. My personal preference is characters that can do so with relatively little risk and/or with allowances for combat losses along the way, and with the potential for large burst in the mid/late game if the early game doesn't work out. Onimaru does this very well, since he shuts down all non-blodge sides of the TD mix-up in the lategame with FA, and also contests throw/blodge with his 7.
Troq actually kind of does that too, with the exception of having to deal with AA/AA mix-ups. He can, however, play Q/AA to only have to lose 20/21 damage on TD losses. He wins those exchanges based on his HP and the rest of his hand composition, etc.