Thinning out bottoms of plants (indoor)

So I have blue dream going right now 2 weeks into bud and the tops of the plants look nice (decent size buds) but the lower stuff is not only not getting light but it does not have any hair and there are mites on it.

If my plants are 4ft tall and the lowers are not getting any light how high should I trim it up? What should I trim off? I have already trimmed them up about 14" but there is still hella arms that are not getting any light and have no hairs.
Will this help with the mite problem? (i have already set off 3 bombs and I am going to spray in a little bit here).

Thanks in advance-

You get alot of mixed reviews on pruning and most people wont agree with each other..Some say prune some say dont..Its really about user preference..I personally trim off the lower leaves because I grow in a scrog

you are going to suffer from the mites but i use everything ie for butter or edibles, its not going to make a shit a difference at this point in the grow due to mites, post a few good pics lets see how bad she is, go get some azamax and quit fuckin with bombs that have very harse chemicals, azamax is all natural 100% organic