1. Block details of building on builder’s company letterhead is fine
2.open car park cannot be sold. You can claim refund of money paid
3. At the time of registration of sale agreement, the builder will have to attach power of attorney or board resolution to show authorised signatory. So builder should not have any problem in sharing the document with you
4. You can approach Rera. Main point will be illegally charging you for open car park. You can also raise points of not annexing block details to sale agreement and not providing power of attorney required for loan sanction
5. If you cancel booking then you will be liable for liquidated damages as agreed in your allotment letter
6. But since you wish to cancel booking, you can approach Rera. This will put pressure on builder. You will get refund for money paid for open car park. But other amount will be refunded to you as agreed in allotment letter in the event the booking is cancelled by you