Hi Ousaima,
1. Compulsions like hair-pulling are (or have been) a strategy to deal with stress. It can be a cortex constellation of "aggression against self" (if it's actually damaging the person's body), or it could have to do with helping oneself to feeling touched, i.e. a response to an unwanted separation or loss of touch.
2. Self-devaluations are usually ongoing beliefs about ourselves, so it's possible to work with them in the "here and now", but often the underlying issue will show up during the work, and it's a value system. If the client can't consciously remember its origin it doesn't matter because the cells and soul can make the connection. The sensation and emotion attached is key. Remember Eve's case of the belief she needs to care for her weight and looks? We believe that this value system was installed where it made total sense so we can accept that and then teaching the client to differentiate the present self from that situation. Again, feeling is key here and persistence needs to be involved.
Does that make sense?