As far as the gradient fill, that’s just an aesthetic that can be added by conditional formatting. Highlight the cells you want to implement conditional formatting with, and then make sure then go to conditional formatting in the Format tab. There are several options whether it is using bars, symbols, or a gradient.
This formula “((Given Cell/cell’s column average) x (weight of aspect’s importance))… [do this for all columns] / (Total weight of all cells/5)”
Does about what you implied it does. It takes in day’s productivity in that certain aspect and divides it by the cell’s average so that it’s objective, and can be used with other cells. Then, this number is multiplied by the importance of the cell (the cells weight). You do this for all of the columns and are given a certain productivity in each of those aspects in comparison to that columns average. Then those are just added up, and divided by the total amount of cells, and then divided by the total amount of weight, just so you can get a productivity on a scale based around 5