I've been following this thread because I have often wondered the same thing. I have separate rices, Arborio for risottos, which I make a lot, and a rice which is sold as "Milchreis" (milk rice) here in Germany. I don't get to make rice puddings much, as I don't make many things which need 2 hours in the oven and I wouldn't switch the oven on just for that.
DH being German, he just doesn't 'get' the joy of a hot pudding, so I'd be making it for just me. (I so miss my crumbles and apple pies.)
Anyway, to get back to the rice, the Arborio and 'milchreis' do look very similar. I could try making a risotto with the sweet rice. Risotto is supposed to be creamy and stodgy and more homogenised, and not consist of individual grains, so it would probably work.
Will try rice pudding in the slow cooker. Perhaps I can freeze some single portions so I can heat them up and indulge in comfort food occasionally.