Bind DNS question


I’m setting up three virtualmin server (master and 2 slaves). My question is I want to configure wich DNS address in network configuration


DNS2= #vultr dns

Here is my questions:

1 - The needs to be the DNS1?

2 - The DNS2 and DNS3 are irrelevant here?

3 - The network configuration in slave zone will be the same as the master?

4 - Vultr offer a DDOS protection, but they alert: “Ensure your server is configured to use for recursive DNS”. In above example I will be able to use the DDOS service? Or I need to put the in DNS1 and in DNS2? Or these change will break the BIND server?

I’m a little bit confused about that…