I never add bread crumbs, I add oatmeal instead and it is great. My meatloaf is about 1lb ground beef, 1/2c oatmeal, and 1 cup or so of leftover cooked veggies (whatever's in the fridge) diced fine, plus whatever seasoning I feel inspired to add, usu. some salt, pepper and one or two other things.
Try the recipe you have with rice flour. I bet it will turn out fine!
I use oatmeal in my meatloaf. A handful of oatmeal, and egg, a lot of worchester, grated zucchini, and grated carrot. Mix it with meat - 1/2 ground beef, 1/2 ground turkey DP's mom makes meatloaf with a can of spanish rice, and it's amazing!