#1 Does it make gaba rice without having to soak it first in a separate pot?
You do not have to soak it because soaking time is part of the cooking function, however, the more you soak it the more the GABA enzyme will be active creating a healthier rice.
#2 How do you get it to go to a “keep warm” setting after the rice is cooked? Just tried it and it does not continuously keep warm, it shuts off.
Mine automatically switches to keep warm mode after cooking using the preset.
#3 Can I cook quinoa, oat groats, steel cut oats, bulgur, buckwheat, barley in this cooker?
They have mixed rice menu but i dont know about how is you like texture. Anyway they can cook any grain.
#4 What's the minimum number cups of rice you could cook this 10 cup rice cooker?
I can't speak to the absolute minimum, but I have done 1 cup of quinoa or rice with no problem.
#5 Can this cooker cook things like stews or pot roast in less time than usual stove top processes (utilizing some sort of pressure cooker feature)?
Yes, it sure can. I've put a whole pork shoulder in it and just like any other pressure cooker, it completes the cooking very quickly.