I'm 37 and I zoom almost every website I use - I also like to be distant enough from the screen. I also very often use ctrl+A to have white text on blue background (I know, most designers will hate me at this point - but keep in mind that I usually sit in front of a screen 12 hours a day, 10 hours a day on weekends...).
Last thing, I just hate sites that use facebook comments - eg techcrunch - because fonts don't scale there. As a matter of fact, I never read comments on those websites.
Seriously consider an alternative. Tweak your browser to your liking. You can always break out into a different browser, if you want to see the site the way the author intended.
I use my own style sheet with opera, and customise firefox flipping between the two, and occasionally breaking out into chrome.
I also find the terminal more readable than the browser, so have made my browser look like the terminal - I even use a monospaced font. Because that is what I'm comfortable with.
W3m and Elinks are actually really nice to use, readability wise.
Funny to read your highlight method, I use that when away from my computer.
Last thing, I just hate sites that use facebook comments - eg techcrunch - because fonts don't scale there. As a matter of fact, I never read comments on those websites.