Designing in reporting

Both field and line items have a right-click menu option called "Size and Position". It doesn't take just any value, especially with Snap to Grid turned on (and doesn't always take exactly what you choose with it not turned on), but you can carefully make sure each line has the same Y value (for horizonal lines). And, if you want them to align and be the same length as the field headers they are underlining, compare each header field X and Width values, and make each line also match that.