You seem to be contradicting yourself here. If you don't want the attacker to take the initiative and dictate your options then I would suggest that you do not wait until the attack is "committed" (whatever that means) in order to try to "find the optional response" but that you make the attacker choose from several sub-optimal responses that you have made available through your own movement. This is a fairly basic strategy that is common knowledge to people in many martial arts.
Actually, there are several choices concerning initiative or "sen". One of them is to allow the attack to fully commit. At the instant of full commitment, it is almost impossible to make a change. There are a number of koryu that practice cutting the attacker precisely at this instant. That doesn't mean that you are allowing them to control the interaction as the mental connection was there before movement ever started and effects the mind of the attacker before he initiates.
I don't think it is a challenging idea at all, but actually a rather simple one. However, by itself I do not think it will be even remotely effective in a physical conflict. I also don't see how it in any way suggests staying confined to your own space or "inviting the attack in." I would think that, in a real conflict, inviting someone who is trained and skilled at attacking to do so would be a very bad idea. Even inviting someone who is unskilled or untrained at attacking to do so seems to me to be needless and unwise.
One of the fundamental principles of "aiki" is that in any technique there is an instant in which you "accept" the attack. You must be at the spot where you could be struck, even if it is only for an instant. This is the whole basis fir "irimi". If the attack is more physical as in a grabbing attack, you must accept the energy and take it into your hara before you try to redirect or you have no real power beyond what is available from your muscle structure.
I am not saying that initiating isn't a sound martial strategy. But it is not the only one. And the idea of control is largely mental; it is on before the attacker ever decides to initiate... This is true whether you are seen to move first, you move at the instant the attacker "decides" to move, or you allow the attacker to move first. Mentally, it's all the same. The Mind is inside the attack before it materializes which gives you complete freedom to choose your timing.
The issue isn't really one of choice but of the ability to overcome the other person's will and ability to inflict aggression upon you with your own ability to remain centered and avoid letting that aggression control you (either physically or psychologically). I find the author's ideas on how to do this to be overly simplistic and out of touch with reality.
You can always spot the "fighters" because they take everything back to physical conflict. If that is the way you look at what you are doing, you miss entirely the benefits of Aikido training for the rest of your life.
Unless you are a soldier on the front lines or are a police officer working the streets, the chances that you will use Aikido technique in a physical confrontation are quite low. I have taught for over twenty years and not a single one of my non-law enforcement / security students has ever used a physical technique.
The Founder had something else in mind in creating Aikido. It was meant to be a trans formative process. It was definitely not about fighting although it utilizes a martial paradigm.
If you take what seems to be effective martially as the model; for your actions in life, you will find that there are VERY few instances in which the martially optimal response applies very well. in most cases the martially based response will only make things worse.
When your spouse presents you with divorce papers, your boss says he is unhappy with your performance, you are having a disagreement with your teen.... these are very real conflicts and they are the kinds of conflicts which folks deal with every single day. Most "attacks" we deal with daily are not physical and yet they are very real attacks. How one chooses to deal with these every day conflicts determines what kind of quality of life one has. If one can let go of the fear based desire to reduce everything to a "fight", one can use ones Aikido to provide all sorts of useful strategies for lining. Far more useful than the ability to enter in and cut down the enemy in an instant.
Over and over the Founder stated that Aikido wasn't about fighting, yet so many people try to take everything back to a fight. What's the attachment to the idea of the fight? Why is it so hard to let go of that and do something that goes beyond?
When O-Sensei lamented that no one was doing his Aikido, it was not him worrying about his students inability to defeat enemies. It was that so few of them saw in Aikido what he saw.
Wendy Palmer Sensei not only teaches Aikido at a dojo but she takes her Aikido out into the world and uses the principles to make the lives of non-Aikido folks better. She deals with conflict every day but it is the kind of conflict that we all deal with constantly and are so poor at handling. Discounting her insights because they don't seem to be the best way to deal with a street attack, which most of us will never do in our lives, completely misses the value these insights have for daily living. I think that is a big mistake.
O-Sensei saw Aikido as a means to transform society and promote a peaceful world. I absolutely believe that tailoring the art to the mind of conflict will never achieve that. Then it's just another jutsu and a rather funky one at that. If it is fighting everyone's worried about, then do a combat art. That makes more sense. But I think that not fighting was much more what the Founder had in mind and Palmer Sensei speaks to that model in what she teaches in and out of the dojo.