Firstly: Leaving Muzdalifah before Sunrise
It is mustahabb for pilgrims to leave Muzdalifah before sunrise. Consensus on this was related by Ibn `Abd al-Barr and Ibn Qudamah.
Secondly: Sending out Women and the Weak from Muzdalifah to Mina First
There is no harm in sending out frail people and women before dawn and after half the night has passed. This is the position of the Shafi`i and Hanbali schools as well as a group of the Salaf. This is the chosen position of Ibn `Uthaymin.
Thirdly: Hastening through Wadi Muhassir
It is legislated to pass through Wadi Muhassir quickly. This is by agreement of the four schools of jurisprudence. A group of the Salaf acted upon this opinion.