You need to use both MySQL data replication and the slave database system. However it sounds like you are trying to do this on 2 different web hosts. Do NOT do this. Your forums will suffer dramatically.

Forget it. These guys are experts and when you ask them how to do something, no matter how ridiculous it is, they'll answer you.

You don't want any fancy replication at all. All you want is regular db backups. These can be done manually via Cpanel. There are also methods to set up automatic daily backups; do a search here.