1) arbitral to arbitral is like service to self even if different branch / office. hence it is not taxable.
2) Q1 a) job work amount should not be included in valuation because it is under exemption notification, even manufacturer is not liable to pay duty for it. Option I to select SSI exemption should be choosen as entire 150 lakhs turnover will be exempt by way of basic exemption of SSI unit. If he do not avail SSI exemption then duty is payable after setting off cenvat credit.