Any tips/resources/guidelines for making homemade pasta with other flours/grains?
You should have no trouble making egg pasta with farro. There are a million different recipes for egg pasta, and as I'm sure you've discovered. It's all about developing the gluten and having a good water content. I like to use two cups flour to two whole eggs plus four yolks, a tablespoon of olive oil, and a pinch of salt. The mistakes I made early on were usually around not kneading enough or using too much flour. 

Rice flour, on the other hand, is another story. It is a lot harder using a pasta machine to roll out flour that has no gluten, so you may want to roll by hand and use for recipes that are more forgiving of the thickness of the dough.