FM-BCS Implementation in live environment

Hi Guys,
I am implementing SAP FM-BCS in already live system which follows fiscal year January to December . Go live date has been set as 31st December hence it is FM-BCS implementation at the end of fiscal year. I am clear about P&L item which will be closed once year end program are executed and hence non reassignment will be required. I have few questions with regards to balance sheet data which is present in system from various module and will need further processing in year to come.
1. No relevant to budget Balance sheet items with open item management c/f to 2019 will need to be reassigned to Dummy commitment item. Please correct me if I am wrong here.
2.There are balance sheet items on line item management which will need processing in 2019 like stock relevant GL accounts (we are using scenario-1 for stock related procurement and hence budgeting will be done on P2P cycle and GI will be irrelevant to budgeting ). For stock GL line item do we need to do any reassignment at the time of go live or they will start getting updated once procurement with budgetary assignment start taking place in 2019.
3. In FI-AA, in all existing assets in co. code I intend to update Fund , Fund center and dummy commitment item. Do I need to do anything for reassignment of asset acquisition related GL line items (I do not think it is viable to do so but still asking ;) )
For other integrated areas like MM,SD,REFX I am clear , I just need to seek opinion on above three areas of any other area I have missed which would require reassignment . Please guide .

Thanks
Atif