Im curious if bean and rice flour would even come close to creating the same texture. The wheat gluten developes its dense "meaty" texture when kneaded a bit, I dont think the others will do the same. I am still interested in trying it, I'm sure flavorwise it would be good.
Xantham gum is often used in gluten free baking so maybe have a google. Xanthan gum gives dough a stickiness similar to wheat gluten but I don't know what it would be like boiled or whatever you're doing for seitan.