Yes you can do that.
In that case, you do NOT configure any logical switch on NSX.
You simply plug the VMs on the vSphere VDS Port Group associated to that VLAN (nothing to do with NSX).
Then about:
. DFW:
You can still use DFW even for VMs plugged on VDS-VLAN_PortGroup.
. LB
You can still do it in one-arm mode (with the Edge-LB connected to the VDS-VLAN_ProtGroup
All good 
Dimitri