Is it important to have "self expression"? How can it be shown? What part it plays in our lives??
Many people don't work for this. Persona, gestures, emotions, feelings, words, writings, thoughts and body language... They all are buts and pieces of you expressing all mentioned above on their limited scale. So, it shows your limited part. Self expression... It is what you are completely along with the mentioned aspects of you.
If you want yourself to be totally known, as in who you are from inside out... You need it! It shows your real traits and qualities.
When we talk about traits and qualities, they come from the "values" we own. And our values come from our morals, ethics, tradition, culture and religion.
So, yes... Self expression is important. It is your value you own and show to others.
Next time you speak, write, give a gesture or use your body language... Remember, you are going to show what You Value Most? And what you are as a whole, being a human being ( spirit, soul, mind, body and heart).