Current State of Active Directory (Server 2012)?

Is it relatively simple to backup and restore an active directory network to another machine without being a windows AD rock star?

You just promote the second server to be a domain controller. Replication will happen as part of the promotion. Transfer the FSMO roles. Run dcpromo to demote the first domain controller, and you're basically done. This process has been the same since Windows 2000 Server.

How about back up if i would loose the machine?

You can use Windows Backup for this. You put the DC in Directory Services Restore Mode and restore the backup. Then, you run a couple of commands to make this permanent and reboot in normal mode. This is well documented on technet and other places. This process has been the same since 2000 server, but the backup software bundled with Windows 2008 and later is much improved.

Is it pretty straight forward?

This depends entirely on your skills/knowledge. What I can say is that it is all well documented.

Is AD (and the services it requires) a lot less resource intensive then they used to be? I'm hoping to only allocate 1-2 GB of ram. Its not like i'll have a lot of users on this domain.

It never was resource intensive. I managed an AD database with over 50,000 objects, and the database was about 500MB. As long as you have enough RAM for the AD database to fit into it entirely, there shouldn't really be any performance issues. I regularly deploy DCs that also run DNS and an anti-virus client with 1 vCPU and 2GB of RAM without issue. Again, this concept and database sizing has been the same since Windows 2000 Server.

It sounds to me like your bad experiences running Active Directory in the past were because of something other than the normal load that is generated by Active Directory.