Here is a technical overview of the relationship between VPython 7 and GlowScript VPython:
An earlier presentation on Jupyter VPython and GlowScript VPython is here:
Concerning publishing your program: If you do not need to import Python modules other than vpython, the simplest publication scheme is to place your program at
glowscript.org, run it, and publish the URL you will see while running. You can also on the
glowscript.org edit page export the compiled (JavaScript) version of your program and insert it in your own web page. You can also reference a GlowScript program like this on your own web page:
<div>This is a test.</div>
<div>It is only a test.</div>
If you save this minimal code in a file with the extension .html, then double-click the file to invoke a browser, it will run.
Publishing a Python 7 program involves other considerations. One option is to use a Jupyter notebook and use the Jupyter mechanisms for publishing a program. I've not tried it myself, but presumably you could modify the VPython 7 machinery to run your Python program on your own server (as opposed to the standard use of a local server) and communicate with the GlowScript library running in a remote client.
As for your other questions, I recommend running this example program:
Then click "View this program" to see how the widgets are laid out, simply by appending to the caption of the 3D canvas.
Bruce