SAP MDGF Validations


We are implementing SAP MDGF for Finance Master Data. I need some help to understand MDGF features:-

1. Is there a standard UI for GL Accounts?

2. Can we customize the Standard UI?

3. Does customization needs development effort or only Configuration

4. By default all ECC validations will be called on the UI?

5. How to add additional validation rules?

6. Can a single MDGF be implemented to maintain master data in multiple ECC systems in the organization. ie., we have 3 ECC systems, each of one branch of business. Instead of consolidating the data can we implement single MDGF governance process on top of all these ECC systems.

7. How to use ECC number ranges? need to call any ECC programs or by default it is configured?

I though of asking all my doubts at once, instead of loop of mails.