Classification of Rental Property as Income from HP or PGBP

I bought a Commercial land on which i Partly built a Commercial Complex and let it on rent, I have been filing it as Income from House Property in past years, but its a part of my Business investment and it takes a lot of time to manage that complex, from maintanence to new agreements, arrangements of multiple tenants, everyday issues etc, I spend a lot of time managing that, Now i plan to build another building and let it on rent, now as its my main source of income and its my main business, 

1. Can i show whole rental income under Income from PGBP?
2. If Yes, (a) Can i file Income from PGBP under section 44AD, as my total rental receipts wont exceed 1 crore ? (b) can i ignore my earlier filing of rental income as Income from HP? won't assessing officer raise any concern?
3. If No, what should be my planning ?

Thanks in advance for answering.