I have an app developed with WAB Dev. Edition with some custom widgets.
Will following scenario work:
Download app from WAB.
Deploy to remote hosting server (the bare bone one, no Portal/Server on it).
Register with AGOL, do all settings etc.
The final result is WAB app on my remote hosting working with data from my AGOL account.
I'm pretty sure it will work, but I like to hear more.
Sure this will work I have several sites setup in this manner. This is a standard workflow when using WAB Dev. Let me know if you have more specific questions.