My experience with rope climbing comes from the school yard, ranger school, and special forces q course. so i have climbed a rope or two. it is all about technique. the worse your technique for climbing is the harder you have to work to climb the ropes.
there are three standard techniques to rope climbing. the first technique and least preferred by me because i cannot do it for squat is the arm only technique. mostly only scrawny south american military types do this. and the rare american.
another technique is to wrap the rope around one leg and stand on it with the other leg. reach up high with hands and slide legs up. once feet have solid grip on rope extend arms full length up rope again and repeat. is a good technique and the one used by most beginners do to ease of use. but not the preferred technique due to drag on the rope from having it wrapped around one leg.
the prefered technique i like to call the "scissor". you grab the rope allowing your legs to hang free. then cross your legs scissoring the rope between them. the rope should be on the outside of the foot centered on the sole while your other foot has the rope draped over its center. then with the foot that has the rope draped over it you stand on the opposite foot creating a break in the rope.
when done correctly you can release the rope with your hands and stand on the rope indefinately. now reach up and hold body in place. once you have a good grip on the rope you release the lock with your feet and the rope offers almost no resistance allowing you to lift feet and regrab the rope. once you regrab the rope using the scissor technique all you have to do is stand up and you just climbed 2 feet of rope by doing nothing more than standing up.
when done correctly the scissor technique will use almost zero upper body for the lift. will only be needed for holding your body in place. if your arms arent destroyed you have done the technique correctly.
as far as descending the rope. place your feet side by side with the rope between them and hand over hand to the bottom. but if the rope is 30-40 feet off ground this can be quite exhausting and difficult to maintain a safe speed of descent so i recommend you use the scissor technique, but allow the rope to feed thru your feet assisting with the friction to maintain a slow safe speed. maintain hand contact to keep yourself on the rope and alternate your hands one over the other all the way down.