I've thought about that very thing especially in regards to the soak and rinse step that many are doing. It seems all you're rinsing off is valuable starch that will convert to sugar and then into alcohol.
There is a difference in what is "lost" in rinsing and what is lost in boiling. What you loose in rinsing is the outer layer of the rice. Especially if you are using a non-milled rice. And when I say non-milled I mean the difference between rice prepared to be eaten vs. one milled to 40% - 60% of its original size to prepare it for brewing.
The outer layer directly beneath the husk is more bitter than the inner layer of the rice. Even in high quality culinary it is highly suggested to rinse the rice very well before cooking.
But when I "boil" the rice all I do is add it to boiling water and reduce the heat with a lid in the pot. Won't all that stuff in the water be absorbed by the rice along with the water?
Sure there are some minerals gained in boiling but the same is gained in soaking properly and steaming. What you are doing is not "Wrong" in my opinion. Just you may get a little better product steaming.