Answer:
Take one royal word in the plural and make it singular by adding one letter
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
A famous home without color and with wings.
They are the shore's gallant knights.
It weighs next to nothing but no one can hold it for long. What is it?
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?