Feats for fighting undead

[GM and the Holograms]

I'm planning on running some very undead heavy one shots for friends because our gm wants to play a character.
One of the players really wants to play a witch, so I'm thinking of allowing him to grab the undead bloodline arcana as a trait and having it apply to hexes as well. This seems like it is equivalent to a feat, so I want to make a few other undead fighting feats available through similar traits.
The only other feat I can think of that is specifically for fighting the undead is turn undead. I don't want to offer command undead as a trait because that would be problematic for the story, they'll have to spend a feat in that if they want it. What other feats could I offer?

[Mysterious Stranger]

Personally I think that is way too strong for a trait. Even as a feat I would be reluctant to allow it a campaign I run because that is something that should be unique to an undead bloodline sorcerer.

Witches have spells that affect undead already. Most people forget witches get cure line of spells on their list. This also allows them to use wands of cure light wounds. If the witch takes the Prehensile Hair hex she can use that to deliver the spells even from a wand. The hex specifies she can manipulate her hair as if it were a limb. With it the witch simple stays behind the front rank and uses her hair to hold the wand to attack with. This may be a case were buying a more powerful cure wand actually is worth it. This could also be combined with the healing hex. Since it is positive energy it does full damage even vs incorporeal undead.

[Imbicatus]

Weapon versatility is a big one for martials against undead. It allows them to deal with dr/slashing or dr/bludgeoning that zombies and skeletal undead have regardless of which weapon they use.

[Louise Bishop]

The Occult Patron gives Command Undead as a spell and this will give a witch more abilities versus the Undead as a 2nd Level spell.

Like MS said the Cure line of spells is also good.

[Paradozen]

Ghostslayer is a pretty great feat for undead hunting.

[The Shaman]

Depending on the level, Deific Obedience (Pharasma) offers various anti-undead bonuses. Most come into effect fairly late, though. I would, however suggest not skipping on generic defensive feats - something like great fortitude could be very good when facing undead.

[Grumbaki]

Just wanted to throw out that a dwarven ranger makes one of the best undead hunters.

Racial
* Barrow Scholar: Dwarves with this racial trait gain a +2 racial bonus on Knowledge (religion) checks to identify undead and can attempt them untrained. This racial trait replaces stonecunning. Source PRG:HA
* Barrow Warden: Dwarves with this racial trait gain a +1 bonus on attack rolls and a +1 dodge bonus to their AC against undead. This racial trait replaces defensive training and hatred. Source PRG:HA
* Shadowhunter (2 RP): Characters with this trait deal 50% weapon damage to incorporeal creatures when using non-magical weapons (including natural and unarmed attacks), as if using magic weapons. They also gain a +2 bonus on saving throws to remove negative levels, and recover physical ability damage from attacks by undead creatures at a rate of 2 points per ability score per day (rather than the normal 1 point per ability score per day). Dwarves can take this trait in place of weapon familiarity. Source PPC:BoS

So this lets the dwarf identify undead, get +1 AC, +1 hit against undead, and hurt ghosts.

Class
* Favored Enemy Undead (+2 bonus on Bluff, Knowledge, Perception, Sense Motive, and Survival checks against creatures of his selected type. Likewise, he gets a +2 bonus on weapon attack and damage rolls against them)

Traits
* Child of Platinum (+1 weapon damage vs undead)
* Corpse Hunter (+1 hit against undead)

Total
* To Hit: +4 (can hurt ghosts)
* Damage: +3
* Bluff, Perception, Knowledge, Sense Motive, Perception, Survival: +2
* Knowledge Religion: +4

All at lvl1. Against undead that is alot of bonuses.

[PCScipio]

Arcane Strike has been FAQed to allow you to hit incorporeal creatures as if you weapon is magical.

[Azullius Koujou]

Possibly go for summoning Psychopomp beings that appear to exist to hunt and feeding on the undead.
Personally especially like "Psychopomp, Esobok"
which a witch can get as a 5'th level spell, so depending on the level you play.

[tonyz]

Great Fortitude (boost vs. negative levels) and Iron Will (lots of undead have various forms of Will-save effects) are both helpful in keeping your undead-fighting character around past the first encounter with undead.

[Claxon]

It seems like the main issue the OP has is that they're worried about the witch player fighting undead.

I agree with Mysterious Stranger that the trait/feat you suggest is too good. Let the player know you are planning to run undead heavy games, and that they will be immune to a lot of mind-affecting things. It's the players choice about whether or not to play the witch, sometimes not every class is a good choice for every campaign. Let the player learn their lesson.