OP, keep in mind you're about 50X more likely to read about a problem on the internet than someone without a problem. Point being reading these internet forums can make you think EVERY RV every made will leak and rot.
Over the last 10+ years I've owned 4 RVs and have never had a leak. And, if/when you do have a leak I'd go out on a limb and say 90% or more of the horror stories you read about are from people not paying attention and not looking around their RVs regularly. An RV is just like a house... little problems turn in to big problems if not taken care of. IMO, there is no reason to tape every seam on the trailer. Just pay attention and be aware and you'll be miles ahead of 99% of people.