Deploying Custom Office 2013, Uninstalling Office 2010

We've just recently moved to SCCM for application and OS deployment, so we're setting up applications to be deployed through SCCM for the very first time. I've read a few guides to deploying Office 2013, and the majority of them follow the same procedure:

1. Customize Office 2013 with OCT
2. Create an application in SCCM by selecting proplusww.msi
3. Edit the deployment type and replace proplusww.msi with setup.exe
4. Some guides reference the .msp in the setup.exe command, some don't. e.g. "setup.exe /adminfile custom.msp"

So, a few questions:

1. Why should I use setup.exe vs proplusww.msi? I understood that the application model gives us more control, better autodetection, and less manual configuration. i.e. use MSI for applications
2. If I should use setup.exe, do I really need to reference .msp? e.g. setup.exe /adminfile custom.msp I thought that when you customize the installer, and place the msp in the \updates folder, running the setup.exe still utilizes the msp file. 
3. Some guides say I should also used an xml file for help with uninstalling Office 2013. e.g. An xml file with Display Level, SuppressModal, and AcceptEula set, then using the command "setup.exe /uninstall proplusr /config .\proplusr.ww\unisntall.xml". What instances would I need the xml, and which instances would I not?
4. Finally, I would possibly like to install Office 2013 during OSD. Would that change any recommendations on how I create the Office 2013 SCCM application?

I'd appreciate any help/advice anyone can give. I was not able to find any info directly from Microsoft on how best to deploy Office with SCCM. Nor was I able to find any info on using proplusww.msi vs setup.exe for deployment. Thanks.