Yes, but ensure: The correct BO ID is used in the application form. The trading account PAN matches the BO ID PAN if required by the registrar.

Yes: All Demat accounts must be KYC-compliant. The names of holders (or at least the primary holder) must typically match with the trading account. Brokers may require additional documentation or…

Yes, you can link multiple Demat accounts (BO IDs) to a single trading account. This allows you to buy/sell using one trading account while holding securities in different Demat accounts.