Now, about Ki / Qi. I don't really believe that I can manipulate / bend Ki to my will (I'm not a monk of any kind that meditates every day and devotes his life for that purpose - hence I'm kinda doubtful that an average person can control Ki). I've came across people that are Ki practitioners. Lots of muscle power is involved - that is what I can say from my personal experience. To me the Ki thing could be explained in my own terms. As my background is tennis, when I play I don't really think about how to coordinate my arm, hips, leg (and the rest of the body) is order to play the ball across the court - that is my intent to play the ball there and my body simply follows. But this only happens because I have spend years drilling that (learning the body movement to actually perform the task), so when I think (intent) about playing the ball across the court then my body knows what to do without me thinking about my body. This way I focus on the game (tactics) rather then on how to get the ball to the other side. I can be wrong, but seems like there is alot of intent work in the internal arts. Based on the logic I've described above (I think its just called muscle memory) it looks like things like : "think your arm is very heavy" needs to backed up with a physical movement (it can be micro movement not really visible to the human eye) in order for the heavy arm to actually work (intent triggers muscle memory action related to it).
FWIW(from me as newbie), your thinking is very much in agreement with mine. Intent and drilling are paramount.
(and you'll need a teacher to tell you what and how to drill and to fix your mistakes, so that you don't drill bad habits and possibly damage yourself irreversibly, whether it's aikido, tennis or internal training)