Buying flat from landowners share

Hello, I am planning to buy a flat in Bangalore which is from landowner's share. There is a MOU between landowners and builder to share 43% and 57% share respectively. There are 4 landowners (3 brothers and 1 sister). The builder share has been sold out completely. The landowners share is left out. When I approached one of the landowner whose wife is actively looking after all the works for the flat, she has agreed to sell one of the flat and said the registration might taken another 3 or 4 months but is ready to give me the possession of the flat to do my interior works and also to move in after signing an initial agreement for sale. I booked the flat by paying 1Lakh rupees and got the copy of legal documents from her lawyer who explained that there are 4 landowners and they are yet to decide on the shares among themselves which might take time but this landowner with whom I have spoken to will be ready to give possession even before registration and so would not be any problem. He also mentioned, if I get a possession before registration and if the registration gets delayed for 6 months or more the landowner might ask for an interest to be paid as I would be already enjoying the possession of the flat for which I have clearly declined. They were also asking me to pay the VAT and Service Tax for this ready to move flat on top of the total price which they had mentioned. I have clearly declined paying that amount and they have now agreed that I will not be paying anything extra apart from what I have agreed. I have now come to know from some of the flat owners who have bought from builders that there is some kind of misunderstanding between builder and landowners and because of which the last finishing touches of the flat was also hit. But because of the intervention of the buyers of the flat, it is slowly getting resolved but has not completely resolved yet. My biggest question 1. Should I go ahead buying this flat 2. If I am buying, can I issue bank cheques in the name of one of the landowner's wife's name with whom I have been talking and negotiating ? Please help !