I have created a nifty plugin for Cura that adds a new category "Printer Settings" to the sidebar. This category contains many of the machine settings that are normally not available from the GUI eg the Nozzle Size, and settings that could make time estimates more accurate.
Note: Changes made in the sidebar override values set in the machine definition or in the chosen nozzle size variant, and end up in quality profiles. This may have unexpected results. It is not recommended to use this plugin unless you understand the implications.
Like other settings, you don't have to make them all visible or even understand what they do. I encourage you to use the Search... on top of the sidebar to find the setting you need.
I have submitted the plugin for availability in the Plugin Browser, but until it is available there you can download it here:
Edit: since posting this, I have fixed an issue where the new settings have an arbitrary order. They are now sorted in a more logical order.