You should never stop practicing the basic principles of Kihon waza. You can even practice them by yourself.
It's not about the principles underlying kihon waza, it's about the principles underlying Aikido.
People often assume that kihon waza is easier than kinonagare. I think this assumption is incorrect, because you get less to work with when doing kihon (no inital dynamic).
At least in my training it's important not to bring the rigidity of kihon waza to kinonagare, but to bring the fluidity of kinonagare to kihon waza (to generate a flow out of a static starting position).
At least that's what kihon waza should - imho - become, once you revisit it after having encountered kinonagare. If you use it the first time around to show the basic pattern of movement, that's fine as well.
My favorite quote regarding kihon waza comes from a Karate blog. It was along the lines of: "To build a house, build a fundament first. But then build a house on it! I see so many people who build fundaments on top of fundaments on top of fundaments!"
There might be a language issue here as well. People seem to use "basic" as in "basic kihon waza" at the same time in two completely opposite ways.
basic:=simple, easy, beginner, initial, starting point
basic:=underlying, fundamental, refined, end product
David, you seem to be happy with your training, so by all means continue with what you love. But I'm more with Mike on this one.