I was surprised to see so little attention paid to regression. Regression is quite powerful and is a powerful thing in a DS's toolkit.

For example: - What is the distribution of the residuals, how does it change over time as data comes in. How Gaussian they are(or not), analyzing weird/oddities especially around the tails - What kind of features offer the most significant signal to the model and which ones are not.

These skills are even applicable to SVM and other classification analysis.