Yeah. I am not an expert and beyond a certain point I throw up my hands, but I understand your frustration. BTW, there is interesting post on text sizes here that you may like ...

I was disappointed that the type maven did not give a conversion formula for pts vs px. Weblogs nowadays come with type specked for pixels. But for those of us with a background in graphic design from before the computer era had worked with pts or maybe in some cases with ems. Anway, I have not come across so far a conversion rate so that if you are using 12 pts on your word processing you would be able to calculate how many pxs to use for an equivalent on yr weblog. This is an important issue for usability especially for more mature people. Pain in the neck, huh?!