When you click on an individual improvement, there is a place where it would make sense to add the improvement description (currently only visible when an improvement is built, which makes many improvement descriptions e.g. the lowest level of life support, ruined structures, etc. never appear in the game).
In the industry allocation tab for individual units, there are two possible good places to include unit stats (currently seen in the deploy and allocate popups and in the combat visualizer). It might also make sense to give units and resources descriptions and to include these here as well.