Setting up OSD in the existing SCCM 2012 environment

Hello Experts,

Please help me on this -

Customer has two Data Centers, DCE1 and DCE2. And there are three SCCM servers in the hierarchy which have been placed in both the Data Centers. Customer requirement is OSD with SCCM.

In DCE1 they have the SCCM 2012 R2 SP1 Primary Site Server and an additional Site System. The roles are configured this way –

Primary Server –

1. Site Database Server
2. Reporting Services Point

NOTE: MDT 2013 is already installed on the Primary server and integrated with SCCM.

Site System A –

1. Fallback Status Point
2. Management Point
3. Distribution Point
4. Software Update Point
5. Application Catalog Web Service Point
6. Application Catalog Website Point

In DCE2 they have another Site System. The roles are configured this way –

Site System B –

1. Management Point
2. Distribution Point

I need help to understand the scenario –

1. DHCP and PXE (DPs) are on different servers and on different subnets, I have to configure option 66 and 67 on DHCP?
2. Since the Primary server does not have DP and PXE enabled, in that case what will be the option for “066: Boot Server Host Name” in DHCP?
3. Is there any additional settings required on the DPs except PXE to support MDT + SCCM?