So Surprise Attack says
A rogue with this ability adds 1/2 her rogue level to her sneak attack damage rolls made during the surprise round.
For a level 10 Rogue, having a sneak attack of +5d6, would you add +5 to each roll or +5 to the total damage from the attack? IE: either 5d6+25 or 5d6+5?
In pathfinder damage roll is commonly used to refer the whole set of dice you have to roll to deal damage from an effect or attack. When a bonus is meant to be added per each die it is explicitly stated.
Compare the reading of Fey Foundling to that one of Point-Blank Shot for an example.
The use of the plural, as per rolls instead of roll, simply denotes every time you roll for damage.
The Unchained versions of Rogue Talents offer slight bonuses over the original versions of those same talents. In this instance, both versions of Surprise Attack grant you the ability to treat all targets as flat-footed during the surprise round, but the Unchained version adds damage to your Sneak Attacks as well.
Given that the additional effects of other unchained talents are quite minor, I would rule that the +5 is added to the total damage, and not to each individual roll.
The Unchained versions of Camouflage and Esoteric Scholar simply removes the "once a day" restriction.
The Unchained version of Combat Swipe allows you to qualify for the feat Greater Steal (the original does not).
The Unchained version of Hold Breath doubles the number of rounds the Rogue can hold their breath rather than adding 2.
