I think you've made some fine points in your post. There is a certain irony though that you need to do other arts first, and it's the no resistance part. Learning about balance is more than just feeling the balance, but how to manipulate uke to breaking the balance. If uke is a stiff board, either do a technique that works in that case, or break him down. That is a skill you never see in Aikido demos. I think practitioners get over reliant on joint manipulation to make their moves effective.
Yeah, there is definitely a certain irony to it, especially since Aikido is so commonly suggested to novices (and generally unathletic people too). You're right, manipulating uke's balance an important part of the process and learning how to break someone's balance forcibly is something that judo is better at teaching at, imo.
I said earlier that Aikido is evasive in nature. You use that evasiveness to get lure your attacker into overcommitting (or unbalancing themselves) then use your timing to take advantage of that.
Another principle that I find myself using in BJJ is the idea of connection. I can reach out and grab my opponent to know where they are and how they are moving. But if they reach out and grab me, I can also figure out where they are and how they are moving. Connection is connection, and even though they might have more direct control, you can control the connection as well.
I think a lot of people focus on the wrong parts of Aikido, which is the handwork, when the true value of Aikido comes from learning how to move with your hara and footwork.
We also did a randori type drill in my BJJ class where 2 people chased down 1 guy and dragged him back to the far side. The solo guy only had to stop the takedowns and prevent getting dragged away. Believe it or not, as ridiculous of a situation as you might see that as, even a little randori experience was helpful in not getting taken down (and more importantly, I was able to stay on my feet and if I were not confined to the area of the mats I could just have walked away).
Now arguably you could say "go train track & field if you want to run". But knowing how to line up your attackers, splitting them up and using my footwork to force them into each other's paths is more than just turning and running. I definitely had a couple easy takedowns just by moving them around them.
People often think it's the joint manipulation that is the essence of the technique but it's not. The essence of the technique is connecting yourself to them and moving your hara around to create the joint lock. The joint lock is the result of the movement. Once the joint lock is established, then you can control the uke.
I agree with you, but that's not what he said. He said the punch was easy and need not be taught. The application may be more difficult but that doesn't mean there is no effort in learning the technique. Boxers don't spend a bunch of time with the heavy bag for nothing. Judoka don't do uchikomi for nothing.
What you're saying is true. I don't think he meant to underplay the importance of learning proper punching technique. But if you weren't studying any striking at all, you could still deliver a decent elbow or punch to their face if you step off their line of attack and step in at a 45 degree angle.
You could teach someone a decent strike fairly quickly. Teaching someone the proper footwork to get those angles is a much harder skill to teach and learn imo. Where technique really shines is when you're able to use your footwork to not only enter in smoothly and quickly, but also to generate power for your strikes.