Issues with not transferring common areas to plot owners

I am planning to buy a plot in plotted development project. The project is not RERA registered. This is in Tier 2 city. The seller is selling the plot at slight premium compared to neighbouring areas due to the development done in the area. Few facilities provided - underground electric cables, street lights, STP on a 1800 sqft plot, relaxation garden on 2500 sqft plot, 30 ft approach roads with concrete and foot paths with plants all the way to each plots. The seller owns the land beyond this developed area. So there is potential for the seller to develop Phase 2 of this project and share the relaxation garden with Phase 2 layout owners. The approach road for Phase 2 can go via the current layout. I have few concerns with this project. 1. The seller is not handing ownership of common areas such as approach roads, the plot on which STP is present, the STP, relaxation garden. The sale deed says this explicitly and says we have usage rights, however, says the purchasers to form the association and maintain this. 2. The seller has collected certain amount as upfront maintenance. This amount if put in FD, the interest can run the maintenance for a year. This is not mentioned in sale deed. The sale deed says the association to pay for maintenance. However, there is separate agreement with the seller for maintenance which might have these details. I am yet to see this agreement and it's details. 3. If the Phase 2 is later developed, how would the maintenance be later split if we, the residents have been owning this up until then ? Mainly, concerns around the seller owning the common areas while the purchasers / owners / residents of the layout pay for the maintenance. How much rights do we have over the common areas ?