I have not seen anyone cook rice uncovered. And if you cover it there is not much point in smoking it. If I was going for a smoked rice, I would cook it like normal on the stove, cool it down, and then put it in the smoker spread out on a cookie sheet and smoke at a low temp for half an hour or so until the rice was hot. It may be kind of dry though.
maby try tenting a pan to cook rice. Meaning just make a tent out of the foil that is open a few places around the side of the pan, but will trap moisture in the top and drip it back down into the rice to keep it from drying?
I don't think you could smoke rice but like scuba said you might be able to smoke the raw rice and then cook it the regular way. Now Paella sounds really good go for it and I will try it if yours comes out. I like paella with a bunch of fresh seafood.