I'm new to this arena so I have one or two questions regarding the P4+.  
Does it have the ability to fly a prededermined mission using a flight plan laid out in Google Earth or similar application? I'm sure this is a basic question but I have not found any specfic article addressing this single ability.

I know there are much less sofisticated UAV/Drones that do that but not seeing it addressed specifically I must ask before spending this kind of money.

Thanks in advance.
Patches

The short answer is yes... It can be done through Drone Deploy. I haven't found any way to do it in DJI Pro or in GS Pro. Drone Deploy will give you a 30 day trial to try it out. Hope that helps.

As already mentioned, you'll need other apps to achieve that currently. One of the most common for autonomous missions is Litchi. You can create a logon on their mission website to play around with what can be done, prior to buying the app. The app replaces DJI GO outright - you don't ever run them concurrently - although initial configuration of your drone is still best done with GO. Many believe that Litchi is also a more stable app than GO too, but that'd be for you to confirm.

Their mission website is here: https://flylitchi.com/hub

If you are asking about the P4 pro +, the answer is NO because you can't install any 3rd party apps on the + controller.
It's easy to load Litchi and do what you are asking about on the regular P4 pro or P4 Advanced.