Activate functioanl area as splitting characteristic

Hi All,

Please clarify below doubts.....

We are using leading ledger with FMGLFLEXT totals table. The funds management (PSM-FM) has been activated.

1. Can we use funds management and cost of sales accounting simultaneously?

2. Can we activate functional area as document splitting characteristic and assign cost of sales accounting scenario to leading ledger even after after activating the new GL? (already there are numerous transactions posted in production)

3. If so, is it possible to update the functional area values for already posted line items?

Thanks in Advance......

Arun