So occasionally and seemingly randomly when developing WinRT apps Visual Studio goes through a lengthy process that starts with \"Creating a new clean layout...\" I would love m
Have you looked at the Windows Dev Center for Win Store Apps? It tells you literally step-by-step what it takes to get it to market. You'll need a dev account, the Windows App Certification Kit, and their approval.
The sandbox refers to AppContainers which were integrity levels in Vista. The sandbox limits/requires explicit declaration for certain privileges.
See Security in Windows Store apps for an idea of how sand boxing/security work.
Windows 8 and RT Windows App Store dev is pretty similar. See this Windows Store app development for Windows RT PCs Whitepaper for some differences.
Hope this gets you started.
EDIT 1:
If you're interested in the MSBuild process, read "Inside the Microsoft® Build Engine: Using MSBuild and Team Foundation Build" and the supplement "Supplement to Inside the Microsoft Build Engine: Using MSBuild and Team Foundation Build". Unfortunately, I don't remember RT being explicitly mentioned, but windows 8 is pretty close.
See App packages and deployment (Windows Store apps) for how apps are managed/deployed from the store (relevant MSDN post).
See also Windows Store Apps with HTML5 Refresh: (05) Packaging and Deployment.