Loan Application in ESS

Hi ESS Experts,

I am using Loan application in ESS..

Standard functionality is working fine..

Is there any BADI to put following checks..

Payment Type, Payment Date and Granted Amount should be mandatory field.. while approver approves the request and Granted Amount should not be more than Requested Amount.   Currently what is happening if approver doesn't mention these details. he/ she can approve the request and then while updating the R/3 system.. record is not getting updated.

and one more check when employee raises loan request.. Repayment Date should not be entered by him/her... is there any way to hide this field.. ?

Thanks

Puneet