I feel like most of Jing's suffering stemmed indirectly from his mother's actions. She treated TSH terribly, and it seems that all he ever craved was his "mother's" affection. He exhibited such a gentle and nurturing nature as a child. However, once he discovered his true identity, his sorrow morphed into animosity, and he channeled all that accumulated rage towards our innocent Jing.
If TSH had been loved by his mother in the same way she adored TSJ, or at the very least, if she hadn't inflicted the wounds she did, his life trajectory might have been entirely different. This could have potentially prevented the predicament with FFYY's reluctance to dissolve the engagement. Consequently, TSJ could have assumed control of the family business, and since FFYY wouldn't have been a factor, TSJ could have openly asked to marry XY without incurring his grandmother's disapproval.
Moral of the story: Irrespective of biological connections, children remain children and are deserving of love and nurturing :)