Answer
(Fatwa: 593/450/D=1431)
(1) The person who is going to perform hajj-e-badal, if hajj has become fardh on him then it is makrooh tahrimi for him to perform hajj-e-badal. And if hajj is not fardh on him, performing hajj-e-badal for him is makrooh tanzihi i.e. but in both the cases hajj of the person for whom hajj-e-badal is performed will be valid. So it is better for you to take such a person who has performed his hajj already. Hajj also would be accepted if you take such a person who has not done his hajj. In first instance, hajj will be accepted with karahat tahrimi and in the second with karahat tanzihi.
(2) Yes, a man can do hajj-e-badal for a woman.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband