Can Weapon Focus be applied to the psychic weapon itself?
Yup.
If you have Weapon Focus: Longsword and you manifest a longsword then you'll get your +1 to attack rolls with it.
Is there a way to WF any weapon I make with the ability? (Without using infinite feats?)
Is there a way to WF any weapon I make with the ability? (Without using infinite feats?)
Not with any weapon, but you can apply it to more than one. A Mindblade gets Fighter Training so a Human, Half-elf, or Half-orc could take Weapon Focus with one weapon and then take the Martial Versatility feat to apply it to that weapon's entire Fighter Weapon Group. Weapon flexibility is a big advantage of the Mindblade, so Weapon Groups that have a variety of types are probably better than the others.
Alternatively you could take Ancestral Weapon Mastery to get a version of Weapon Focus that can be moved around among your racial weapons. Mindblades are proficient with all martial weapons so an Elf (or Half-elf with the Weapon Familiarity alternate racial trait) could, with 10 minutes of practice, transfer the effects of Weapon Focus between any of the following:
* Longsword (martial, one-handed, 1d6, 1d8, 19-20/x2, S)
* Rapier (martial, one-handed, 1d4, 1d6, 18-20/x2, P, finesse)
* Longbow (martial, ranged, 1d6, 1d8, x3, 100 ft, P)
* Longbow, Composite (martial, ranged, 1d6, 1d8, x3, 110 ft, P)
* Shortbow (martial, ranged, 1d4, 1d6, x3, 60 ft, P)
* Shortbow, Composite (martial, ranged, 1d4, 1d6, x3, 70 ft, P)
* Elven Curve Blade (exotic, two-handed, 1d8, 1d10, 18-20/x2, S, finesse)
* Elven Branched Spear (exotic, two-handed, 1d6, 1d8, x3, P, brace, reach, finesse)
Half-orcs can do the same with:
* Falchion (martial, two-handed, 1d6, 2d4, 18-20/x2, S)
* Greataxe (martial, two-handed, 1d10, 1d12, x3, S)
* Orc Double Axe (exotic, two-handed, 1d6/1d6, 1d8/1d8, x3, S, double)
* Orc Skull Ram (exotic, two-handed, 1d8, 1d10, x3, B, reach)
Dwarves have the largest selection:
* Battleaxe (martial, one-handed, 1d6, 1d8, x3, S)
* Heavy Pick (martial, one-handed, 1d4, 1d6, x4, P)
* Warhammer (martial, one-handed, 1d6, 1d8, x3, B)
* Dwarven Boulder Helmet (exotic, light, 1d3, 1d4, x2, B)
* Dwarven Maulaxe (exotic, light, 1d4, 1d6, x3, 10 ft, B or S)
* Dwarven Double Waraxe (exotic, one-handed, 1d8, 1d10, x3, S)
* Dwarven Waraxe (exotic, one-handed, 1d8, 1d10, x3, S)
* Dwarven Dorn-Dergar (exotic, two-handed, 1d8, 1d10, x2, B, reach)
* Dwarven Longaxe (exotic, two-handed, 1d10, 1d12, x3, S, reach)
* Dwarven Warhammer (exotic, two-handed, 1d10, 2d6, x3, B, reach)
Most other races get very little from this approach.
Thanks for the interaction help. :D
You are welcome. :)