Why does the base of an exponent have to be greater then 1

It's not 1 that is exactly the problem. It is also 0. And perhaps - 1 although that is a lot trickier than the other two.

Let's start with one. It give 1^1 = 1 for a power of 1. It gives 1^2 = 1 * 1 for a power of 2. It will give 1^100000 = 1 for a power of 100000.

So the base can be 1 but it is known that any power won't change it's value.

The same can be said of 0. 0^1000 = 0^1 = 0. 0^0 is really a bad dude. You won't learn about that for awhile.

(-1) ^11 is different from (-1) ^10. The first gives - 1 and the second gives 1. So you have to be careful with - 1.

There is nothing wrong with (1/4) ^3. The power of three and the base of 1/4 are fine. The answer is (1/4) * (1/4) * (1/4) = 1/64 which is perfectly good answer.

It works for negatives too. (-1/2) ^3 = - 1/8