16px or 1 Rem is the industry standard, and I beleive that’s what Eelements uses for it’s base font. But there is no law saying you have to use that as the base font, especially if you have a site that doesn’t have alot of text on it.
I use the base font for my paragraphs but I also incorporate lead paragraphs which is usually 18px in places where I want the text to stand out.
I’ve been grappling with that, too, but waiting to see what happens with Typography (and Markdown) first. I’d like the final component of what I’m using done before I start fiddling with the Theme Studio on it.