Absolutely yes.Not just pull-ups but every other body-weight exercises are the best strength builders. In fact, for Kids to whom hitting the gym is a big deal, they can always rely on body-weight exercises to build strength.
pull vs chin
Any average men should manage to hit 7-8 reps of pull ups with acceptable form. Those who can do 10-15 reps are considered as fit and those who can manage more than 15 reps are considered as Strong.
Yes, It is just perfect to do pull ups and chin ups on the same day. Both these exercises work the same muscles it’s just the emphasis that is different. So it is ideal to perform them on the same day.
Yes, Your muscles need rest in order to grow. Rest is as important as diet and workout. Doing pull ups every day will lead to over-training and will kill your gains.At most, you can do pull ups every alternate day.
This is because our body uses back muscle and biceps partially when we do chin ups. Whereas for pull ups our body depends more (like 90%) on our back muscle alone and hence doing pull-ups seems tough compared to doing chin...