I would focus far more on real food, versus nutrition-speak for something like this that is intended in large part for general-public consumption:

I would create food groups like "Leafy Greens," "Other Vegetables," "Meat," "Organ Meats," "Fish," "Fruits", etc. I would list several examples in each category and offer guidelines on how many servings per day (or week) one should try to eat.

I know this isn't perfect, either...but I'd like to see a bigger emphasis on focusing on foods, meals, sunshine, living healthy -- the RDA stuff may be a necessary evil, but I believe it puts too much focus on nutrients and things science doesn't fully grasp.

RDA is really a useless benchmark for the purposes of good nutrition. They were created in the 1940s by the Food and Nutrition Board by way of depriving test subjects of a particular nutrient, vitamin or mineral and seeing at what minimum dose symptomatology developed for deficiency.

This means the RDA is a minimum to avoid becoming sick due to vitamin/mineral deficiency. Hardly a standard for health.

The Optimal Daily Allowance (ODA) is a much better standard, based on scientific evidence for maximum health, not just avoiding deficiency. You can learn about it here, and there is a chart here breaking down all the facts and ODAs for any given nutrient. Don't forget, these may greatly differ from person to person based on health, age, sex, Rx, pregnancy, etc... Although generalizations can be made, good nutrition can also be highly personal.

You should really do some research before questions like this. Don't assume anything, because in this instance your assumptions are very wrong. It is hypothesised our ancestors got up to 16g of Potassium per day, 4 x the RDA, with less Sodium than in the modern diet. So infact Potassium is too low, far too low considering how much sodium we get, because it appears it is the ratio that is also important. Some searching of potassium just on this site should give you plenty of information.

I'll start you off: The Evolution-Informed Optimal Dietary Potassium Intake of Human Beings Greatly Exceeds Current and Recommended Intakes http://www.seminarsinnephrology.org/article/S0270-9295(06)00143-4/abstract