4Q: We have valence electrons and conduction electrons in a semiconductor. Do we also have valence holes and conduction holes ?

Answer :

We have valence electrons in the outer orbit of a semiconductor. We have conduction electrons in the conduction band of semiconductor at 300 K. 

When an electron jumps from the valence band to the conduction band, a hole is created in the valence band at the place from where that electron jumped.

There is no such concept of valence holes and conduction hole. A place void of electron is a hole.