Remove the possibility to add records with the blue +-button for lower levels 

The blue "+" button does NOT make any sense for lower levels, as the record will disappear and will not be added to a higher level.

It only makes sense to add a record to the top level by means of the blue button. For lower records, you have the "+Add record" button on the right hand side.

Why is the change necessary:
usability, ease of use, no frustration for user (cause record will not disappear)