I have a 2000 cherokee. Looking at getting some new tires. Want to know if size 30X9.5x15 are going to be too big and rub the wheel wells?

You would get only some MINOR rubbing when you are offroading. With a stock Cherokee you can't go any larger than 31x10.5 but I wouldn't recommend anything larger than a 30 because of the added stress on the drivetrain, brakes, and steering components. A 30x9.5 tire will work perfectly and make your Jeep look even better. What tires are you planning on getting?