Hi, I obv have some difficulties with the cryptographic foundations, but bare with me and please do help me understand, despite some questions being silly.

What does happen when the Hashrate keeps growing immensely, and the difficulty continues to go up? The difficulity is determined by the number of leading zeros in a hash and the target (remaining digits in the hash), correct?

Is it correct that the difficulty per definition is bound somewhere and can't continue to grow indefinitely?

Should it not be more likely to come to Collisions when there are less degrees of freedom, i.e., digits that can be different from 0?

In the scenario described above, imagine the difficulity is as high that there needs to be 63 of the 64 digits of SHA to be 0. What happens when a block is virtually impossible to be found would the Blockchain stop / fail. (63/64 is exaggerated but you get the drift)