Problem when booting OS X from an external USB drive
You do not need Unibeast (a tool for hackintoshes) to create an external installer. Can you confirm you're only using it to run the createinstallmedia command provided by apple as per this page?

Apart from that it seems you are confusing an external Mavericks installation with an external Mavericks installer. All you should have to do is double click the installer, straight from the App Store still laying in /Applications on your internal drive, then pick the external volume as a target (wipe the current ones and make a new one for the entire stick). Using all-apple tools should make that go smooth. 

Then just boot from the external stick by holding down opt at boot, and complete the guide. 

When in doubt or in need in help, always boot in verbose mode to get more information, and above all, do not over complicate things.