Ninja Tricks: Combat Trick vs Style Master

[Ragex]

Any reason to pick Style Master trick instead of Combat Trick?

Style feats are listed in combat feats, this means I can choose them with Combat Trick, I don't find any sense in the existence of Style Master, also considering that for both tricks you have to meet the prerequisites.

Bonus question:
Why Style Master say "that she qualifies for as a bonus feat" but Combat Trick no?
That's mean that i don't have to meet the prerequisite?

[Melkiador]

Quote:

Unless otherwise noted, a ninja cannot select an individual ninja trick more than once.