Navigation and Tools
1. Stop chasing button.
All menu and tool buttons should be easy to find. ONE Navigation menu and ONE tool menu.
2. Predictable regardless of device
As many people use both desktop and mobile back and forth. You should not rethink when you move to a mobile.
The basics of accessability are font size, background color and font color. My rule of thumb is no smaller than 18px fonts.
My rule of "thick thumbs" is no button or clickable area should be smaller than 42px. A compromize between design and usability. This "two level menu" is designed with mobile in mind. The traditional admin menu with accordion menus is good, but is harder to manage on mobile.
Things changes over time and it should be easy to add new stuff without start over. The "two level menu" makes it easier to add things without being too hard to navigate.