That's about what I'd expect with regard to your front axle weight. Fifth wheels have very little impact on front axle weight because they have no leverage on it. I haven't ever owned a toy hauler but my understanding is that they're typically a bit heavy on the pin/hitch to account for the fact that they are designed to carry a lot of weight behind the rear ale. Your pin at about 18% isn't overly light, but I'd also be curious what you'd lose with the garage loaded up.
New tires can make a big difference for the first few hundred miles, especially aggressive AT or MT type. After breaking in they tend to settle down.