That is a lengthy post but I skimmed it pretty well and will just reply.
You want to start facial exercises.Touch your lips together into a flat kind of surface which will drag your jaw down... do clockwise motions 250 times... then reverse to counterclockwise 250 times. Once this is done you want to shake your head vigorously.. Like your in a hard rock metal band. Let your cheeks giggle a little.. if you start feeling liteheaded.. dizzy.. soreness.. than your doing everything correctly.
Naw I am just messin with you.. You cannot target one area to fix.. If something is wrong with one area.. you have to work all areas of your body to fix it meaning... You want a more defined face.. shrink the belly a little to stop chubb rubb. You don't have to add this, that, that, this to work. Start with a proper eating plan as this is 85% part of your success. Then since its fat you want to lose.. start on some cardio. HIIT is a great way to drop weight.. or bf %, and not lose much or ANY muscle. Set a goal for yourself.. and start on it.. as your belly shrinks.. everything is turning more define from that lack of fat that surrounds it.. your face will go down in size.. and to tell you the truth.. what I noticed most when I started this a while back.. is I notice my face was the first part that I noticed a differance in.. Good luck bro!