You don't have to wear a tire out before you change it. It may be worth fitting different tires for the raining or dry season months, keeping you part-warn sportier rubber for more suited conditions. You'll get more grip from a road tire in wet weather. It'll last longer too, and you'll be saving the stickier stuff for the dry season. Ultimately, it may save you money.
To select tire you need to get a notepad and pen and be honest with yourself. How, when and where do you ride? Calculate the approximate kilometers you do on the road and race track, plus what type of roads they are.
A tire such as Pirelli's Diablo is designed for roughly 70 percent road use and 30 percent track use. On the other hand, the Pirelli Diablo Corsa is the opposite, 70 percent race track and 30 percent road. Do you ride that much more on the track than you do on the road? Also tires have a tread pattern for a very good reason. The grooves disperse rainwater and by moving they also help the tire warm up quicker too. Track tires have large areas of tread with no pattern to give the tire a better contact patch with the ground in dry conditions. This gives better grip, especially at full lean. But on the road in the rain, you need a tread pattern to push the water aside to keep the tire in contact with the road, and to help it warm up, and maintain the tire's specific optimum operating temperature.
Full-on race or trackday tires are the most specialized of all. They'll be designed for the most specific criteria, such as working on billiard smooth surfaces. They'll also be designed to work at the much higher temperatures generated by constant aggressive and fast riding. When you're not riding that fast and aggressively, you don't generate enough heat for the tire to reach its optimum operational temperature. Traction will suffer and you'll get cold tearing. The constant stopping for traffic lights and crossing people, noodle shops and tractors also means the tire will cool down, before warming up again. Track tires aren't designed for as many heat cycles as road tires, so they'll go off quickly.