Is it possible to open folders with just one click in Mac OS 10.11? Renaming could be done using context menu with right click then.
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.