the sacd part doesn't play nice with standalone dacses.
The real advantage imho of sacd is you get masters that the studios are at least giving lip service to sound quality. I don't think you'd be satisfied with the results from the oppo, however. A better bet would be a sony ES or denon player that you could later have modded, or a pre-modded unit.
I'd think making 100% of the grade the final exam is what would make students take responsibility for their own actions. Giving them 50% just for showing up penalizes people who understand the subject matter and don't need to go to class for the remedial education. If they can ace the final, why does attendance matter?
My only problem with castille soap is it tends to be overly drying. I do like the dr bronners tea tree oil bar soap. When I'm feeling particularly greasy tho, I do still shower with the hemp castille soap. I usually follow it up with a moisturizing soap tho.
If 0db doesn't overload your input, it's fine. The right way is probably to use a voltage meter, and set it to 2v. The easy way is to do it by ear
Since it's powered by usb, I'd probably set it fairly low, and let the GS1 do the work.