I really like serif for headers, but find it harder to read for body
text. Sans always feels like it lacks "authority", serif always seems
to grab the attention better.
Hm.
That's really not grabby/authoritative enough?
Incidentally I just noticed that Safari on MacOS Catalina will not display "webp" images.
Would you feel better if the section
headers were serif as well?
Not really. It's not so much the serifs themselves as that it's so "pointy" -- all the corners are much sharper than anything else on the page.