I think it is good that you can set your own preference for font size rather than that being defined by the webpage designer; my own preference is much smaller than 16pt. I also dislike the narrow page width, and prefer it to fill the window; it should be the user's job to set their own preferences (there are browser extensions to apply your own CSS to webpages; I use this to alter the styles of many webpages, including even Hacker News).

I generally design webpages with no CSS at all (and no scripts either); it can use whatever preferences the user has set in the browser configuration, instead.

I agree there are too many useless images. I say: do not include any images at all unless it is a major part of the article. Stock images are not helpful. (Again, I sometimes use CSS to suppress them.)

I agree with you no popups, no fixed headers/footers/sidebars, no popup share icons. (Many kinds of share icons should be outside of the scope of the document anyways; you do not need to include them at all. The user can use a browser extension or bookmarklet or something to do sharing if wanted. Anyways, the document author does not necessarily know what the user wants to share, with whom, and how.)