Windows Store app, when to use touch / keyboard

I’m porting my game for the Windows store, I’m wanting it on Windows Phones and also on Windows desktop (PCs & laptops etc).
I think I’m right to be using the Cocos2d-x 3.9 proj8.1-universal solution for all I need here?

My main question is, how do I know when to be using touch controls (phone/tablet) or actual physical keyboard (laptop) ?

My first thought was to put a define in each of the two project files (Windows 8.1 and Windows Phone), my thinking that the Windows desktop uses the Windows 8.1 project, and the Windows Phone uses the Windows Phone project.
But I’ve discovered that Windows tablets use the Windows 8.1 project also (why don’t they use the Phone project when they’re surely more similar? :smiley: ).

Any ideas, this information is hard to come by.

*edit, or maybe I need to use the following solutions/projects for the following devices???
Windows Phone (touch screen) - proj.win8.1-universal solution / Windows Phone 8.1 project.
Windows Tablet (touch screen) - proj.win8.1-universal solution / Windows 8.1 project.
Windows Desktop (physical keyboard) - proj.win32.

Is the proj.win32 suitable for the Windows Store?