There are many ways to get to tools in CR2Edit 6. In version 5 it was necessary to open a file first in the main window which loaded all the information about the file. Now you can go directly to a tool and open the file and only the information needed will be processed saving time especially with today's large files. If you do have a file open choosing a tool will not make you open it again.
If you know where the tool is you can click the "T" on the button bar and have access to the primary collection of tools.
If you like hot keys there is a set of them they are user changeable.
Another option is the Index accessed with the I button on the button bar. This is a list of the most often-used tools alphabetized. As Zeke says it's easy to use. It closes automatically when you click on a tool.
Which method is up to you whatever is most comfortable for the way you work.
The primary tools window
Help in CR2Edit6
Requirements and Ordering