Looking for help for multi-vdom with 1 NAT / 1 TP

1st adventure with FortiGates...

We have 2 FG-60 in separate sites with 7.2 running - I need to run transparent mode, as we cannot change the subnet for data traffic.  We would like to retain the fabric features, so multi-vdom configured like split-vdom seems like the proper solution.  Split-vdom is removed in 7.2 or before (can't remember what ver).

The documentation starting on page 1848 is helpful, but leaves me with questions.

If I am going about this wrong...pls suggest the right answer 

1.  Can I use 1 WAN Port for the Root/Traffic VDOMS?  I have 1 port on the upstream router

2.  Can I connect my FG224D switch stack to 1 Data Port and have fabric & data traffic safely segregated?

3.  We will also deploy Fort APs - something special needed? 

Thank you ,

Morgan