Tapioca starch can be found in Asian markets in small 400 gram bags. This recipe uses two of those. Each bag weighs about 14 ounces. You can also find tapioca starch in Latin markets.
You could substitute another flavorless oil for the canola - sunflower, safflower, or grape seed. Olive oil is too strong.
I've never attempted to make these dairy-free, but I have thought about using Daiya vegan shreds, a good tablespoon or more of nutritional yeast, and a non-dairy milk. The eggs cannot really be substituted, however.
It's important to let the dough cool before rolling into balls. If the dough is too warm, the baked rolls will flatten. Not the end of the world - more of an aesthetic thing.
This recipe makes a lot, so you can freeze half for later. Just form the dough balls and freeze, then put them into a plastic ziploc bag. You can bake them when they are frozen, just add about 5 more minutes to the baking time.