I can provide a little info but don't have all the answers for you:
For (2): Like I mentioned in the other thread, the place we got was a furnished house rather than a serviced apartment, but they did help us find a person to help us with the cleaning and washing. Dr. Uma was the one who set it up for us.
For (4): We found that Dr. Biraj was usually in her consultation room around 11 am local time here. So maybe you can try calling the hospital at that time. In case you are not able to reach her, Dr. Uma may be able to guide you with information. I live in India, so did not ask this specific question, but for our baby we we told to use Nan Pro 1 which is available here.
Regarding the milk bank, I am not aware of any signup but you can check with Dr. Uma. We requested our surrogate to extend her stay after the initial 15 days which is "included", so that we can provide the surrogate mother's milk for longer. We paid for her stay at the hospital and a daily rate for her. On the first day we had to give the formula milk for our baby since our surrogate was not lactating yet and they were not able to provide us milk from the milk bank. After that on some days when we did not get enough milk from our surrogate, they were able to provide us milk that was excess from other surrogate mothers. It looked like they did this at their discretion and using their judgement on who needs it more (I guess underweight/premature babies are given preference, our baby had normal birth weight).