Does this mean that I only apply the bonus to one hit ever throughout the course of the game, or once per combat, or something else?

Does this mean that I only apply the bonus to one hit ever throughout the course of the game, or once per combat, or something else?

Certain abilities (the Linked and Auto-Fire qualities, as well as two-weapon fighting) allow you to get multiple hits with a single attack roll; Deadly Accuracy's caveat just means that you only apply it to one of those hits, in this case.

It still seems broken. Looking at my my friend's Wookie. Just into the third adventure he has melee 2 and Brawn 4 dealing sizeable damage on Rivals and Nemeses.

Well He'll have to spent loads of XP to reach DA (I think he said 95) but given that he then can easily dedicate on Brawn and might have picked up some ranks in melee along the way, he will deal Brawn (5) + 3 + Rank 4 (perhaps) + successes = 13 Damage on a hit (piercing 2) enough to down two minions in one attack.

Well on the other hand he won't be good for anything else for a long time as XP will drain into that project for quite some time...

Look at the mercenarys improved field commander abilty thats earlier on the talent tree, assuming a 3 presence and 4 leadership, You can grant on a succesful average check everyone an extra maneuver(beyond the 2 limit max even) at the cost of 1 strain per person. On a triumph they get an extra action. They can do this every round. Thats a greater damage and/or advantage potential, just imagine everyone getting 3 maneuvers in and an extra attack also every now and then. The higher rank talents can be quite powerful, the characters are heroes after all.

Also the nemesis characters you make up can have the same talents remember.