2. Two years is about the most you're going to get out of tires on a dual axle trailer.
4. You want longer lasting tires, get radials but you're still not getting much past 2 years on a dual axle.
Not true. I have (3) tandem axle trailers & my used tires on these trailers, are over two yrs old. And I'm rough pulling trailers, drive fast, heavy breaking etc.
Stihl Kombi System
028 Super, 066 Chainsaws, PP 800 Pole Saw
F-150, F-350 Trucks
Ariens Rear Tine Tiller
5x12, 6x12, 6x14, 8x16, 7x18, 6x22
Asus Transformer Infinity TY700 Tablet
If you think it's expensive to hire a professional to do the job, wait until you hire an amateur.