Hi, Alex, in my opinion your approach is not the best.
And, of course this question must not be mandatory, if only the rows are clicked which has to be changed.
I'd recommend a question of type "multiple short text", where you
either display the attributes in the subquestion text (as you did before), saying "Enter the corrected value or leave blank"
or place the attributes into the answer field as "default answer", saying "Correct it or leave it as it is"
You may use an array(text) as well.
Joffm