Fathers Self-Aquired Property Distribution

Hello Sir, I appreciate your help here to all the legal advice seekers. Here is my situation. My father died 10years ago, we are three kids me a son and two daughters, my dad always wanted to give me all the properties which are self-acquired because he thinks he gave already too much to my two sister when they were getting married as ‘dowry’ but he died suddenly (heart-attack). He started transferring all the properties one by one on my name but at the time of his death there are few more left. The reason for my dad wanted to give me all is i gave him lot of money when i was working in USA, with which he constructed a house and bought few properties, now there is old property which suddenly got so much valued that my sisters are asking for share..my mother is my side and she also wanted to give me all of it (no share to daughters), here is the important thing which i need your advice on, when me and my mom went to MRO office to ask him about the options he suggested that as a he can transfer the land to my mom’s name as there is a law to do it and then after that my mom can transfer to my name at her will is this true and legal to do? if yes will there is a chance in future that my sisters can fight for it? 2) I had sent so much money to my dad when he was alive (i have all the proofs banks transfers/deposit slips) will there be any advantage that i can claim all his property based on this?. I have red about the Hindu Succession Act 2005, does it still say that daugheters still get the Fathers property if they dint took care of his labilities?. 3) As i said i sent so much money from USA to pay-off his debits and maintanance, based on my contribution can i get all the properties?. 4) While searching the documents in my father locker i found a will in which he stated all his properties should go to My Mother after his death, this will is un-registered and written on 20 Rs stamp paper with two witness signed, can i use this will to transfer the properties to my mother name and the get the partition deed on my name with out my sisters knowledge?. 5) What are the chances that a will is challenged by my sisters, as they are not aware of such will exists till today. What if Witnesses are not alive now?. 6) What are the exceptions to Hindu Succession Act, in my case i am robed by this law as my sister are taking advantage of this against my fathers will. 7) There are some properties purchased by my father with money i sent from USA but got them registered on his name since i am residing in USA, what are my options to stop my sisters in claiming the share in those properties?. 8) Since my mother know my dad's oral will as he want to give all the properties to me, she is in full support to me, how i can get the properties transfered on to her name and then to mine?. Thank you.