Unity + HTC Vive + SteamVR Newbie Question

Hi,

I'm awaiting an HTC Vive and plan to use Unity to build a demo. I wanted to make sure I have everything planned out in my head around how to do things so I can hit the ground running as quickly as possible.

One thing I've not been able to find anything on and I was hoping someone could help with is probably a quick easy one!

When I build my Unity project for Windows and get the resulting .exe and data folder, will I need to have the full Steam Platform + Steam VR Plugin for it to run? Or is it possible to build and run a SteamVR app for HTC Vive without having the Steam platform installed?

If it does need the Steam Platform is there a need to register as a developer and submit stuff to Steam?

Sorry for the probably silly question! The stuff I'm working on won't be anything that would ever go into Steam so hopefully I don't need to install it.