Adding As Confirming Party Or Consenting Withness

I have recently entered into a sale agreement for a plot in Bangalore. Where the owner (PARTY A) has asked a builder to develop his land of 4 acres into a layout. As part of this development, the builder (PARTY C) has registered an agreement with the owner to sell few plots which he has mentioned as a development fee to the builder. As well the builder has an investment amount for the same. 1. My plot is part of the portion where the builder has Right to Sell(registered with 20k) as per the agreement document. 2. I have carried out an sale agreement with the owner and an assignment agreement with builder. Is this ok. 3. Earlier we had prepared an draft SALE DEED mentioning Party C(Builder) as CONSENTING WITNESS as part of the loan authorities requirement we had to modify Party C(Builder) as CONFIRMING PARTY is this OK . Do we need to keep the Party C(builder) as CONSENTING WITNESS or COMFIRMING PARTY. 4. Do I need to raise an agreement to cancel or nullify the Right To Sell of