HA Active-Passive | Some configurations points

Hi all,

i'm going to configure HA Active-passive, i'm reading many topics, but are not more detailed

i need to know these: ( On auxiliary device)

1- What is the ip address to set on Port 1 (lan) on auxiliary device.Is't the same one on the primary (Gateway of lan network)?

2- If i choose port1 as auxiliary admin port , can i set the same address above (question 1) or another address but in the same LAN subnet?

3- what about password admin, encryption backup key and secure storage master key , will i configure them on auxiliary device?

4- can i select all ports to monitor except the ha link port?

5-what about " DHCP and PPPoE interface configuration and Cellular WAN configuration must be disabled": 

             > is this prerequisite for HA active-passive

             > do I have to do it on the two devices !  i don't understand this point....

6-can i create HA zone and type it DMZ on the two devices?

I think I made the rounds on the ambiguities...

the config is simple, but i need to understand all these points 

Thanks to all