Someone who is contented is satisfied, gratified, or satiated.
The related nouns are satisfaction and satiety.
Happy, Elated
Yes, uniqueness is a word. It is a noun that means the state or quality of being unique or distinct.
Flight means the state of being airborne.
patriotism
I'm pretty sure it means, in those terms, the adjective/description, not exactly state, of being important.
"Flexibility" typically refers to the state of being willing to yield to others and adapt to different situations or needs.
The word is "flexibility." It means the willingness to adapt or adjust to others' needs or opinions.
content
The root for oblivious is obliv- which means unaware. The word means a state of being unaware.
Yes, legality is a real word which means lawfulness or the state of being legal.
The suffix is -ate. This suffix means state of.
Serene means extremely content or peaceful.
The suffix -ity means the state of. In this case, the state of being creative.