Re: Ki and Technique...
As all topics of Ki wil have a million opinions...here is one.
IMHO, you cannot correctly perform the "technique" without the application of KI.
Viewing KI as a separate and distinct phenomenon from the physical aspects of practice will cause you issues...if not physically, then mentally in the appication and understanding of aikido and martial arts in general.
I personally leave my KI stuff as experiential. That is, I experience it as I learn and grow, do not seek to apply it, harness it, or cultivate it directly.
To me it becomes one of those Koan things in zen. If you seek it directly...it will escape you just as you find it.
Although as you state...a good Kiai certainly never hurt and is, IMHO, a verbal/physical manifestation of KI that can focus your energy and strength when needed!