>

My first thought would be that you might want to rebind that function to some other key that's easier to hit without clawing your finger. You could also try putting an o-ring on the keycap to reduce travel distance I suppose.
Hello Friends, i bought my first MechanicalKeyboard on ebay (it is an Akko ACR59). Sadly, the Key for the Questionmark aint working. I unpinned the key and pushed the button under the regular key (on the board, if you know what i mean), but it just aint working. 
What can i do now. I dont find an option in windows to say that another button should do the questionmark. 
Can someone help. >

It's hotswappable, so you can try removing the switch (presumably it came with a switch puller; this is NOT the same as the keycaps that you already took off, if i am reading your post right) and seeing if it has bent pins/swapping it with a different key's switch.  
There's also probably some AKKO software that will allow you to remap which key does what if all else fails. >

This worked! Thank you! I would have never thought, that it is saved on the single buttons. Holy... Man Thanks! >

How would one fill a hole on a PCB? 
I bought the Maestro TKL with Cherry MX browns by Archisite, a Japanese company.
One problem is the B key feels really clacky and feels like somethings stuck inside. Also only the B key switch is upside down (The Cherry sign is on the bottom). They probably reused the PCB for Quattro, another of their keyboards with a pointing stick, that's why.
I changed keycaps and soldered another brown switch on, it got better but still feels clicky.
But the Quattro keyboard doesn't have this problem, so I suspect it's the gaping hole that they left on the PCB that is the problem.
How would one plug the hole on a PCB board?
It's a circle with a diameter of about 7mm I guess. >

Have you tried the tape mod on the back of the pcb before doing any permanent mods on the board itself? To plug the hole I would try to do something that is reversible. Backing tape and hot glue to fill in the depression. >

my left little finger hurt from playing on my new keychrome K2 with brown switches. I was playing game where left shift is pushed for running all the time, 4mm travel distance and stronger weight than my usual keyboard.  Plus maybe I pushing that key not straight down but with side of finger. 
what do you thing is solution, change the way or strength of pushing or some lighter linear switch? switch with less travel?
It hurt so much next day, I can barely bend it.