As a previous post referred, yaw control is a big problem, but also the coupling to other axes. Using a proven design will give you a fighting chance. Even Northrop started with a tail then gradually deleted it. Modern designs (B2) have an active flight management system to keep the rubber side down. A good reference is "Tailless Aircraft in Theory and Practice" by Karl Nickel and Micheal Wohlfart. It is rather pricey new, but used copies can be found from time to time. It is a good read and will give you something to start from. I have experimented with flying planks for years, some work better than others. I needed a fin on all of them, yaw stability is especially noticable when the bird is getting slow, as in the 180 to final. Good luck.