aj,
Based on your knowledge and approach to these questions, I have to believe you were trained as a physical chemist. I am a simple synthetic organic chemist (i.e. a cook) and the way you poop out clear, correct and scientifically sound answers to all manner of questions here constantly impresses me.
I will continue to toss out my half-arsed answers to questions here, waiting eagerly for you to gently fill in the blanks, nudge me off the guardrails of chemistry, and complete the answer.
To illustrate, I did my calibration solutions on a lab balance I bought off eBay, good to 0.1 gram, calibrated with a set of weights from the lab at work, didn't bother to dry the sugar, and was happy to have made close enough calibration solutions that showed good agreement between my two hydrometers and one LHBS-sourced refractometer. I used RO water because I had some, to check 0 and since have found that my tap water is close enough to keep me happy.
Good enough for this old cook...