Average air-pressure that is used on Cubs is 8psi. Keep in mind that there are variables, pilot preference, terrain and elevation, just to name a few. The tires are rated at a minimum of 8psi to keep within established manufacturer and FAA testing limitations for optimum wear.
We do not have a determined life expectancy for the tires. There are too many variables. We have heard that some haven't lasted a single season, because of the terrain and consistency that they were run, and we have heard of others that are still going strong that were built before we were a full fledged company. It is also highly recommended that you rotate your tires, depending on your use, either every 100 landings or every annual, and rotate them on the wheel, not just from side to side. This helps to keep the wear even across the tread surface.
Yes, weather checking can and will occur in all rubber products. Alaskan Bushwheels are a rubber product, and after time weather checking can become a problem. We cannot eliminate this problem, but we do the best we can to deter it. Since we took over the business in 2000, we have not had any checking problems with our tires. We keep our rubber formulas current with all of the up to date amounts of UV protectants, waxes and oils and make sure that all tires meet and pass a rigorous set of tests before they are put into inventory.
Tire covers are a good idea. But we recommend that you make sure that the material has a UV protectant.
We also recommend the old fashioned build your own out of plywood and paint it with a UV protectant paint. The bonus of building your own is that the open space where the box slides down over the axle actually allows for air to circulate and heat doesn't build up around the tire, helping to eliminate the natural curing process of the rubber.