Kim,
I am not an expert on scales so I don't feel qualified to comment on your results using the scale you noted. The special scale I mentioned that I use is the MyWeigh 300-Z, which I purchased a few years ago on eBay. A photo of it is shown at
http://www.myhealthmyworld.com/My-Weigh-300-Z-Pocket-scale.html. That scale is supposed to be better and more accurate in measuring small quantities of ingredients, especially lightweight ones.
The 70.3% figure you mentioned is indeed the hydration for the dough made using your dough recipe. It is calculated by dividing the weight of water by the weight of the flour. If those weights were correctly and accurately weighed on your scale, the corresponding hydration is 70.3%. It is hard to say whether that is too high. For most flours, such as the two flours you mentioned in your opening post, the hydration is typically 56-62%. However, there are doughs recipes where the hydration can be 70% and over. I would have to know more about the style of pizza the recipe is supposed to produce to be able to comment more intelligently.
A typical range of salt values for pizza dough (and bread dough as well) is 1.5-2%. However, some people like to use more, but usually below 3%. But, 3.52% salt (your measurement) is more characteristic of a dough that is intended to be used for acrobatic dough tossing contests. In those applications, the salt is made intentionally very high (in the inedible category for most people) to toughen the dough so that it can be used in acrobatic dough tossing.
Another point to keep in mind is that ingredients like salt and sugar are hygroscopic, that is, they pick up moisture from their surroundings. That could lead to weights on a scale that are higher than using a comparable ingredient that has not yet picked up moisture from its environment. There may also be age-related or storage-related variations. There are also different measuring spoons to take into account. They are made from all kinds of materials, they come from different manufacturers with different manufacturing facilities, and they can come in different shapes with different manufacturing tolerances. These variations can lead to different results when weighing the exact same materials on the same scale.
When I was involved in the design of the various dough calculating tools, I had to come up with conversion data for over forty different ingredients. Rather than using my scales to do the conversions for all of those ingredients, my first line of attack was to rely on either government data, such as available from
http://www.nal.usda.gov/fnic/foodcomp/search/, or the data in the nutritiondata.com database at
http://www.nutritiondata.com/. If I could not find the nutrition data for a particular ingredient in either of those two databases, I used the data given on labels for such products to the extent they were available. In some cases, I found that there were multiple sources of an ingredient, such as vital wheat gluten. In many of those cases, I averaged the conversion data for the multiple versions. It was only when I could not find conversion data for a given item anywhere that I used my MyWeigh 300-Z scale.
It would be impractical for me to suggest to our members that they all go out and buy more scales in order to get more accurate weights for items like yeast, salt, sugar and oil when the conversion data for such items, that is, volume measurements, is likely to be more reliable across the board, and certainly easier to use than using the scales. My recommendation is to use the scales to accurately weigh flour and water, and occasionally oil if used at high levels, and use the volume measurements for the other ingredients. Of course, if one were making commercial size batches of dough, using scales more widely to weight the larger quantities of ingredients would make sense.
Peter
