Re: Commitment into the attack
The issue isn't commitment to the attack, it's commited to attacking. In Aikido training all we expect of uke is to commit to that attack, first and last. If it so happens nage wasn't able to harmonize the first time, but didn't die from the first attack, uke should make his 'final' attack again.
If we have uke committed to fighting... Then I guess it'll be different. Sometimes the encounter is over from the get go but uke still fights on oblivious to the fact. By then, if it hasn't already degenerated into a sparring session, it would inevitably lead to one with both uke and nage busy trying to do something to one another.
It's a fine line indeed to accepting an attack and initiating one of your own. So much depends on your ability to blend with uke's energy that sometimes it seems easier to just attack his being instead. Wrong... And can only get you so far.