Mathematically accurate rules should be taken very literally and require no "explaination"
Of course they do. For example, it seems you assumed an infinite set, when the set is actually 1-11.
"to be clarify", this is not how averages typically work. zeros are supposed to affect the average. you can define your own averages, but you create biases. This system does not find the best unbiased estimator of the average score.
The scale starts at one, so there is no way to give an album a zero. If you don't like an album, put it at the bottom.