Nick,
FYI ATP in APO is a prerequisite for using BOP in APO. BOP doesn't 'know' anything about the ECC ATP, so it can't calculate any availability unless ATP is being done locally in APO.
Also FYI there is an analogue to BOP in ECC transaction V_V2. Although limited in functionality, I have seen programmers torture this ECC software with enhancements into doing things that SAP never dreamed of.
Q1) Can we have BOP in APO to start after a particular date that is say after planning time fence .
It is possible to create a filter that selects orders based upon one of the dates contained in the order, this is standard configuration. A variant for this filter could be "select all orders whose requirement date is greater than today plus 30 days" and perform BOP only on them. Little or no programming required.
However, what you have asked is to create a filter that selects orders based upon a date that is calculated, and that calculation includes a field that is found in the product master or the planning version, and calculated based upon the contents of a timestream. This would require a bit of programming in an enhancement, but should still be do-able.
Best Regards,
DB49