If you grant a character with Flurry an extra attack, do they get the benefits of the CE that granted them the original attack, For instance, Say Obi-Wan Kenobi, Jedi Padawan gets Mon-Mothma's Death Attack, and rolls a 20. Does he Still swing at +4 +10 on his flurry attack?

No. Mon Mothma is allowing you an immediate attack at +10 damage. This only happens once. If you rolled a crit then
Flurry Attack comes into play as a seperate immediate attack.