Making use of Possessed Hand

[EisenKreutzer]

Possessed Hand and it's assosciated feats fascinate me.
How do you sqeeze the most oomph out of this feat chain? How deep do you dig into it?

Obviously the real meat is Hand's Autonomy and it's TWF bonuses. Hand's Sight is also pretty good, granting immunity to being flanked, but it seems to pretty much negates the TWF bonuses since it needs a free hand to work.

Is there something I am missing? Are there more hidden gems here, some interactions with other feats, classes or archetypes that are worth noting?

[Aldrakan]

For a swashbuckler they're fighting one-handed already and don't make Concentration checks, so the initial feat is decent for them, and they don't lose anything from Hand's Sight. At higher levels the Concentration penalty doesn't hurt a magus too badly either.

[Ellrin]

Possessed Hand and it's assosciated feats fascinate me.
How do you sqeeze the most oomph out of this feat chain? How deep do you dig into it?

Obviously the real meat is Hand's Autonomy and it's TWF bonuses. Hand's Sight is also pretty good, granting immunity to being flanked, but it seems to pretty much negates the TWF bonuses since it needs a free hand to work.

Is there something I am missing? Are there more hidden gems here, some interactions with other feats, classes or archetypes that are worth noting?

The Possessed Hand feat tree is really neat, but it doesn't have any synergy with itself. Possessed Hand is better for a non-caster, due to the concentration penalty, but Hand's Detachment most benefits characters who can gain familiars--mostly casters. Hand's Detachment also makes the rest of the feats in the tree useless, at least while you're actually using it, and losing up to four feats, even if only temporarily, just to use a fifth isn't a great trade-off. As you mentioned, Hand's Sight doesn't function nicely with Hand's Autonomy, or even Possessed Hand (since you lose the +1 insight bonus on attack and damage unless you're using unarmed strikes or natural attacks with your empty hand).

You can get some nice benefits out of almost all the feats, but it seems like taking all of them together is generally a bad idea.

[Necroticplague]

Technically, it doesn't look like Hand's Autonomy actually requires any of the wielded weapons to be in the posessed hand to get the TWF reduction. So if you have more than two hands or hand-substitutes, you can multiweapon fight and still get Hand's Sight bonuses. Dips into Alchemist, White-Haired Witch, and so on, are standard ways of getting this.