havent got a complete answer
but if we had hair on our palms , we would not be able to grip things as well , things would slip out of grasp !
and soles , if we had hair on our soles we wouls slip , we would have no grip
its all do do with evolution when we were apes etc.. we needed to grip with our hands and feet to survive !
as for lips , i presume its to do with eating and drinking
and we dont have hair internally due to the make up of the skin !
our follicles direct hair to grow outside of the body xx