Hi, I think you may be able to do the whole setup in a fairly easy way. You can try the following:
DSL-2730E:
-Use PPPoE mode.
-DHCP On
Netgear R7000
-WAN: Dynamic IP
-DHCP On
Connect the WAN of your router to any LAN port on the Modem
----------
This way, all the 4 ports on you modem and...