Grammatically speaking:
* Crazy can act as an adjective, but it's often considered informal and can have negative connotations. It's better to use a more precise adjective if possible.
* Quick is definitely an adjective.
* Pretty is also an adjective.
Figuratively speaking:
* Crazy quick is often used as a phrase to emphasize the speed of something. It's not a single adjective, but it can be used in a descriptive way.
In conclusion:
* Quick and pretty are definitely adjectives.
* Crazy can be an adjective, but it's often informal and can have negative connotations.
* Crazy quick acts as a phrase, not a single adjective, but it can be used to describe something as very fast.