Apple "option" keyboard shortcuts and touch typing
I had a similar issue but solved it in a different way.

I simply "modified" the keyboard layout to the level it suits my needs and uses.

If you press and hold a certain key example "a" a pop up will show me all options for it.



Here is how it works.

Find a file in /System/Library/Input Methods/PressAndHold.app/Contents/Resources   that is your keyboard Keyboard-??.plist (in my case it is called Keyboard-de.plist (German keyboard)

Copy that file to your Desktop (to modify it) since you can not modify the original file.

Open it (it will open in Text mode)

Find for example the "c" it looks like this (and I added the Portuguese ç)

&lt;key&gt;Roman-Accent-C&lt;/key&gt;
    &lt;dict&gt;
        &lt;key&gt;Direction&lt;/key&gt;
        &lt;string&gt;left&lt;/string&gt;
        &lt;key&gt;Keycaps&lt;/key&gt;
        &lt;string&gt;C Č č Ç&lt;/string&gt;
        &lt;key&gt;Strings&lt;/key&gt;
        &lt;string&gt;C Č č ç&lt;/string&gt;
    &lt;/dict&gt;


now add any "c" accents you like to use (Open the Character Viewer and find it) and just drag it over to the text file. 

Once done replace the original keyboard-??.plist file with yours.

Now you have a highly customized keyboard specific to your uses, and no need to remember some finger breaking key combination to get it.