Very valid points. Does it come down to the fact that uke is not competing with uke and so is 'dumbing down' his own training to allow nage/tori to achieve smooth technique. i.e. although you talk about a counter strike, that is probably not what I would do if someone was taking e.g. ikkyo - I would use their own ikkyo against them for a counter technique. However we all have to learn in the first place.
Can we say what a realistic reaction to these techniques would be? I think 'deflecting' rather than 'blocking' is very valid. But peoples actual reaction may vary o an atemi. Some attackers focus on one strike, others do combinations. Some will want to grapple, whilst others will want to back off or strike.
I think one benefit that aikido has, at least in the UK, is that in most real situations people are completely suprised at your body movement, even the moving off centre line.