that is why probably ikkyo is the most important and most difficult technique in aikido because it relies purely on timing. You can only make it work if the timing is perfect.
I'm not sure I can agree with the above statement, on any level. Why is it the most important? why is it the most difficult? Why does it rely purely on timing?
It is difficult for us all to comprehend aikido and as such, we can discuss it endlessly here on this site. Personally I like ikkyo, I find it really easy, of course timing is important, depending on the dynamics of the attack, but purely? surely not, there is so much more that has to be in place for the timing to be effective (distance, balance, structure, relaxation, mind, intent etc)
I don't see any of the aikido techniques/exercises as having a hierarchy of importance, they are all useful tools for practicing the principles of aikido, which I see as the raison d'etre of aikido.
I am not saying that you are wrong, as I would be interested in why you say what you say.