In my 5 years of riding a Ural and following them on the various web boards, I have never herd of a single instance of Ural denying a warranty claim. Almost everybody mods their rigs, and off pavement adventure riding is their intended and advertised use.
IMO, Ural/IMWA has the best warranty and customer support in the motor vehicle industry bar none.
Sidecars and trikes are completely different, trikes are easier to ride, but are more limited in almost every other way. If you are going to ride off pavement, a sidecar is far better.
Neither is anything like a 2 wheeler, it is a whole new set of skills to learn, and you must unlearn your 2 wheeler skills.
"Take care, sir," cried Sancho. "Those over there are not giants but windmills".