EDIT: Since i would be using delay() in the loop for other funtions, how can i prevent the interrupt timer settings messing with the delay function.
The simplest way is to put that crutch away. Do not use delay() for any purpose. It is not needed. The blink without delay example shows how to get along without it.
so basically i want the arduino to control servos and go to a certain position
Piece of cake.
generate a 4KHz sound
What kind of sound? Why not use the tone() function?
record sound
The same one you just generated? Why? Can't you remember what you did?
The Arduino make a lousy audio processor. How are you going to measure the sound you want to record? How often? For how long? Record the data where?
This seems like a dumb question but do i even have to use interrupts to perform sound generation
You, or some other function, yes.