Hi,
BCS activation has nothing to do with carry-forward of commitments or with commitments as such. BCS is a special regime for budgetary documents only. So, if you don't have any documents in 2014, you have nothing to worry about.
As for FMGLFLEXT, why do you speak of automatic assignment? Activating PSM-FM and selecting totals table for your NGL ledger are two different activities and performed separately.
Regards,
Eli