open folder with one click

Solution 1:

It's not possible to open folder with one click in default "Icons" view in Finder. However switching to "Columns" view (cmd-3) will allow you to open folder with one click.

Also it could be faster to just use hotkeys instead of trackpad/mouse. Use arrows to navigate inside "Icons" view, cmd-down to open selected folder and enter to rename selected file or folder. When no file or folder is selected, you could just type in file/folder name and Finder will select closest match for you.