1) I think it would be better if we allow users pick any Google Font they like
2) Also it would be amazing if the font can be changed in the settings, for example for "h1-h6" and "p" they choose and forget about it. The same with font size. Users will save 70% of time they adjust each sections.
3) Is admin will add a lot of Google fonts in the dashboard will it somehow slow down the page load?
