Lots of problems getting the Sieve calcs in the Lab Testing Module to work right

I've just recently begun adding the Lab Testing Module to our gINT capabilities. Our lab currently uses Excel spreadsheets to do calculations on and report lab data.  For sieve analysis, the lab most often does unsplit samples, which are moist to begin with, and first dries the total sample to get a moisture content, then does a wash on that dried sample to measure the -#200 fraction (running water on that dried sample through the #200 sieve, ASTM D1140), and then dries the portion coarser than #200 again and weighs it, for a dry sample to put through the rest of the sieves. Our lab uses cumulative weighing for recording sieve data after shaking the soil.  The weight of the portion 

The problems I'm having with the Sieve table in the Lab Testing Group are many:

1.  For samples that have a moisture content in the Sieve table, gINT apparently calculates Percent Finer on the basis of the equivalent wet weight. This is not correct according to ASTM C136, which states that the percentages passing should be calculated "on the basis of the total mass of the initial dry sample."   Using the wet weight gives incorrect % Finer and really messes up the classification. I don't really want to reinvent the wheel and re-write my own custom formula for Percent_Finer, I can't find the actual code anywhere and this would be time consuming.

2. I'd like the Wt_Total_Spec to be able to be calculated/populated from the Water Content Coarse Dry Wt + Tare and the Water Content Coarse Wt Tare. How can I do this? 

3. Whenever I have any data in the Water Content Coarse field (or the 3 fields used to calculate it), and select Weighing_Method as "Cummulative" (annoying that this is misspelled by the way), after I enter the individual Soil+Tare Wt values, I cannot save - I get an error message "The sum of the 'Soil + Tare Wt' for coarse sieves must be less than or equal to 'Wt Total Spec'."  But this should not be the case for cumulative weighing - only the last/highest weight must be less than or equal to the Wt Total Spec.  Am I missing something?  

So far overall this is not very useful to my organization, with the above issues and the fact that it looks like I will need to write several gINT Rules for certain things, which I haven't yet learned how to do.