DHCPv6, Prefix Delegation and fixed IPv6, howto

Hello dear IPv6 enthusiasts 

I read through many messages and I am still uncertain about the exact syntax or more the behaviour if IPv6 with DHCPv6-PD and fixed IP addresses.

I found this http://community.ubnt.com/t5/EdgeMAX/Version-1-6-0-IPv6-Comcast/m-p/1169289#M55531 article, answered by UBNT-stig) most helpful, but I am still a bit stuck for use of IPv6 without slaac but with fixed adresses and DHCPv6 on my LAN.

(and still I am missing a CLI reference for all the EdgeOS commands).

I would be happy to compile all my knowledge into a kb article and share it to everybody.

Example:

    ethernet eth6 {
        address dhcp
        description WAN
        dhcpv6-pd {
            pd 0 {
                interface eth0 {
                    prefix-id 1000
                }
                interface eth3 {
                    host-address ::1
                    prefix-id 2000
                }
                prefix-length /48
            }
            rapid-commit enable
        }
        duplex auto
        speed auto
    }

So here my questions.

1. Is it really sufficient to set the configuration for the IPv6 of eth0 and eth3 in the section of the WAN PD 0?
2. Does radvd automatically assign the corresponding /64 Prefix (as /64 is default) for the internal networks (eth0 and eth3)
3. What would I need to configure, if I would like to do stateful DHCPv6 inside my LAN segments? Assumption my Provider would give me a fixed prefix, would it be ok to omit the whole PD configuration and write the needed configurations directly into the devices section like this example?
   

       ethernet eth3 {
           address n.n.n.1/24
           address n:n:n:1000::1/64
           description "something"
           duplex auto
               dup-addr-detect-transmits 1
               router-advert {
                   cur-hop-limit 64
                   link-mtu 0
                   managed-flag false
                   max-interval 600
                   other-config-flag false
                   prefix n:n:n:1000::/64 {
                       autonomous-flag true
                       on-link-flag true
                       valid-lifetime 2592000
                   }
                   reachable-time 0
                   retrans-timer 0
                   send-advert true
               }
           }
           speed auto
       }