Re: 7 lessons from my first responsive web site

1. Does this example constitute a single page app (SPA)?

Yes, at least it fits the Wikipedia definition for SPAs:

https://en.wikipedia.org/wiki/Single-page_application

Personally, I tend to differentiate between "applications" which merge
database content with HTML vs. "sites", which essentially serve static
content.

If this is an SPA, then it shows a very simple, responsive SPA requires
little in the way of JavaScript libraries or frameworks.

Good observation and point. I've opined a couple of times lately that most
JavaScript and CSS frameworks are overly scoped, which is a difficult
position to take because some are so popular.

2. Are there pitfalls to modifying the site layout based on the content
being loaded into the page?

I don't have enough experience with SPAs yet to have a good feel for the
constraints one may run into as the complexity and functional requirements
increase. I hope to gain that kind of experience.

The site has a light blue box extending across the page containing the
site theme (i.e., "Social hope is faith in the ability of human beings to
care for each other"). I would like the site theme to show only on the home
page. I would like it hidden on the other pages to give more scree real
estate to the content of the page.

Rather than writing JavaScript to show or hide content that applies to just
one page, how about just embedding that content in just one of the pages?