Date conversion warning BODS 4.2 SP3

I am getting the following warning message for date fields

Cannot convert string <0> to date using format string <yyyymmdd>.

Cannot convert string < > to date using format string <yyyymmdd>.

Cannot convert string <      00> to date using format string <yyyymmdd>.

The system has been around for a while and the source data quality is poor.

There are around 81 dataflows in a job and many columns use to_date function for conversion. ( all data flows are direct mapping with only date conversion)

Some Data Flows has million records.

The source and target are Oracle / SQL Server and use ODBC connection.

1. Is there any way we can skip writing the warnings without modifying the job ?
2. When there are lots of Warnings  it is  overwriting in the Monitor log file and the Monitor in Management console is empty. Hence unable to see the progress of the job. Any solution to this ?
3. Job which usually completes in 9 mints took 38 mints to complete. Due to more warnings ?
4. Many places i have used ifthenelse(field in ('','0'),'',to_Date(field,'yyyymmdd')) and removed lots of warnings.But another day it gives error in another source. So any other way to ignore the warnings.

Regards,

Divya