My lady, you expressed so many valid and truthful facts in all you wrote about those three magical words.
"I love you"
Inside these words is a conveyance, or self awareness if you will, of feelings we have for those these words are given. I agree with every point and detail of what you expressed.
All to often we as humans fear love. We fear as you said rejection, and denial of those feelings by those we express them toward. We shirk from love, shy away from it and are intimidated by it.
Why?
Because we are frail and sensitive by nature when it comes to opening our hearts. Fear of the unknown has always been the one trait humans could not and cannot conquer.
Winston Churchill expressed it best when he said "The only thing we have to fear is fear itself."
Loving and saying I love you are the most precious of things in our lives and to fear saying you love someone should not be a deterrence from those wonderful and beautiful feelings it brings us.
I only add one thing more to what you expressed. Not only is it important to say "I love you", but so very vital to add all the reasons why you love someone. It is not enough just to say you love, but also to show and express why you love.
We were given the most incredible gift in being able to love. To squander and fear this gift only brings us misery and emptiness. Sure we are hurt and left with scars inside when love goes awry. To give up on love and fear it is to give up on life itself.