OS Backup of SAP data + DB parameters for Oracle

Hello!

I have installed two SAP ECC 6.0 systems landscape with Oracle 10 on windows.

Now I would like to set up the backup strategy for the whole relevant data, including

Oracle and OS, such as \usr\sap\..

For the DB I implement Online backup weekly, and redo logs 3 times a day.

Now I would like define the backup strategy for the OS data, such as \usr\sap\... and have the following questions:

1) How often should I backup the SAP-Binaries-partition \usr\sap\...?

(daily, weekly, 1 times month)

2) Should the DB, SAP R/3 or some Services be stopped for this issue?

Do exist some file-locks avoiding offline backup of \usr\sap\... ?

3) What should be backuped from \usr\sap\...?

(trans, profiles)

And the last question regarding the setting for the two DB-parameters, because I get warnings from DB-check:

db_block_checksum

statistics_level

Thank you very much indeed!

regards

Thom