Graham - I'm intrigued by your comments that if you limit the techniques of Aikido it's not Aikido? Are you suggesting that everything is Aikido? In which case the term becomes meaningless neh?
Aikido is an art of principles, not techniques. There is a story of O'Sensei breaking the arm of a karateka, this is very different to the view you have when you look at some training. The method O'Sensei used to develop Aikido was to take the techniques he learnt from Takeda and made them Jiyu Waza. From here O'Sensei developed the principles that make up Aikido, that is what was required for him to defeat hi attackers.
Atemi (hit the body)
Kiai (spirit shout)
Hitoemi (avoiding the attack)
Enten Jizai (Attack and defence as one)
Maai (spatial awareness) O'Sensei used to talk about the old tradition of Mizu Uchi or Suigetsu (moon and water)
The list is longer, but not limitless. Implement these principles and the technique is unimportant, master them, and awareness, and there is no need for technique!
So if your attacker is a BJJer who is going to take you down and choke you out, harmonising and blending will mean you knock him out. I prefer open hand strikes to the head. A well placed gyaku yokomen to the chin will achieve the same result as a hook. Other wise I suggest an elbow. This is how we train our irimi for kote gaeshi, elbow to the chin, body to the elbow.
The technical syllabus for Aikido did not appear until after O'Sensei's death in 1972. That is why in O'Sensei's terms you have Ikkyo (first teaching), Nikyo (second teaching) etc. I just wish someone could tell me what we were supposed to learn in each of these teachings. Specifically, with the subtle difference between the omote versions of each "techniques". Maybe one day with enough kenkyu I will figure it out.