I also use MindNode to visually break down problems I am trying to solve.
You can install the theme from here and open it in MindNode. Here is how it looks:
Mind map everything - How I use mind maps to effectively transcribe knowledge digitally and visualize thoughts and knowledge I have for both myself and for other people interested.
⌥ + delete will delete currently selected node only unlike delete which will delete the entire branch.
I can label connection arrows.
I can embed links in notes.