Hi there, here are some answers to your questions, hope this helps!:
1) Hardwired means that something is genetically determined. Imagine your brain as an electric circuit, hardwired means that the connections in that circuit are permanent and can never be broken. Here are some other examples with hardwired:
'Our ability to learn our native language is hard-wired.'
'Some people believe that they were born with a talent which was hard-wired.'
2) Yes, as far as I can understand from context, function would mean result here.
3) Scratching is a term used in DJing, where the DJ creates a sound by using their hand physically to move the record forwards and backwards on a turntable. Here is a YouTube video which shows what it is, when you see it on video it will be a lot clearer than my written explanation!: https://www.youtube.com/watch?v=wh9o0nG3brg
4)This one is really difficult! To expound is not a very common verb, it means to explain something in detail. Other synonyms could be 'present' or 'put forward'.
It is quite difficult to get from context, but I am pretty sure that here it means that the DJs are kind of explaining the history of physics through the high quality of their DJing. In other words, they will be DJing so well that it will expand our ideas of what is physically possible. Breaking the laws of physics basically through their excellent talent.