[rule interpretation 3rd party] "Athame knowledge" magus arcana

[Myth27]

athame knowledge:

Benefit: The magus forms a much closer relationship with his weapon. The power turns her weapon almost into an extension of his body. The magus can spend 1 point from her arcane pool as a swift action to reach out into the history of the weapon to learn its secrets, casting her mind back through time and space. For a moment, she literally embodies the weapon’s history and use. Consequently, the magus gains the use of one feat of her choice that directly improves her use of the weapon, such as Weapon Focus or Improved Critical. The magus must meet all of the feat’s prerequisites to gain it; a magus with the black blade class ability uses her magus class level in place of her base attack bonus. The feat remains with her for one minute per magus class level.

TL;DR: the magus gains the use of one feat of her choice that directly improves her use of the weapon

What do you think is meant by that? Anything that increases attack, damage or critical? Any feat that is for a single weapon? Something else?

For example would you consider this feats valid?
Arcane Strike
Deadly aim
Reckless aim
Bullseye shot

[Westhart]

I believe the intention was for feats such as improved critical (X weapon), or weapon focus (X), not feats that allow you to use a weapon in a new way, but feats that specifically apply to the chosen weapon. So I do not believe those feats would qualify.

[Kurald Galain]

For example would you consider this feats valid?
The arcana is badly written. That said, all of the feats you mention improve her use of the weapon. A feat that indirectly improves her use would be e.g. Dedicated Adversary.

[Myth27]

The arcana is badly written.

Yeah I agree, I decided not to use it for this reason

Anyway, thank you both for your answer