Certainly no expert here either, I just shoot from the hip mostly.
When I filed for MY business name to be recorded in Hawaii there was no 'law' that said I had to do that. The reason I filed the NAME was to protect it from others using it. That filing, in Hawaii, only protects me for (I think) 4 years at a time, then I have to register it again. If I don't register it I suppose I MIGHT prevail in a court of law, but if a BIG DOG wanted the name, I wouldn't have the resources to fight them for it. I would simply loose control of my business name. Which would be a major blow to doing business, I could 'start over' with a new name. Yeah right, and give up a hard earned reputation among VERY confused clients? It would be a death blow to loose it.