When you talk about Ki, especially in Ki Aikido, is it "something" you can sense in your body, "something" you can collect here or send there in your body, "something" you can "pack" or "move in your body?
Said in anonther way: Is it similar to what is experienced as qi in tai chi or qi gong?
Honestly Carsten, I have no experience with tai chi or qi gong so I can't equate what I feel to what is experienced in those arts. When I have coordinated mind/body and someone pushes on me I don't move. When I do move under a load I do so not because I'm being pushed but because I choose to. With a coordinated mind/body I have no need to control uke in the sense that I make him go where I want him to go. He will go where he goes and I'll go with him, leading as I follow him.
To answer your first question, what I refer to as Ki (coordination of mind and body, One Point, correct feeling...) is something I can definitely sense. I feel it more as a state of being than a force like gravity, electromagnetism or the strong and weak nuclear forces. It's not something in me, it's me.