Regarding optimizing redux, there are some well known techniques: memoizing, using reselect for example.
But there is one that remains unknown to many, although it’s simple and very efficient: The connect’s areStatesEqual option.
Edit: I published react-css-variables, which makes defining CSS variables easy using a React component.
CSS variables are a game changer, they allow easy and cleanly separated JS-CSS communication (among other things !).