Google sold SketchUp to Trimble, a multi-billion dollar company which sees it as a strategic resource. Trimble has already hired some additional developers and is looking for more. In short, SketchUp is NOT abandonware.
There are a number of videos (both free and paid) on how to use SketchUp, as well as several books. The SketchUcation forum is also very helpful. If you are willing to give it a real try, I think you'll find that it works well for you.
Mike Bostock's D3-based Hive Plot demo is an excellent showcase for D3, Hive Plots, and their excellent synergy. D3's detailed graphics and highly interactive feedback make hive plots "come to life", showing off their defined and predictable diagram layout, as well as their high data density.