Hari,
One issue strike my mind ... while payroll data load is running in BW make sure no payroll postings are running in source. If payroll postings are in progress in ECC and your BW data load got triggered then the load will fail with lock issue .
error message:
Posting runs are locked. Restart the transfer later Errors in source system
This is one thing you can make a note of it... make sure you check with business what are the feasible times when you can run your BW data loads so that there won't be locking issues.
FYI: We are using 0HR_PY_PP_2 payroll posting documents data source which also extracts amount from PCL2 cluster table.
You might also face the lock issue as you are also trying to use the Payroll transaction data source.
Regards
KP