Within the Special Modifications book, it lists 3 different template profiles.

1) Prosthetic Appendage: Replace functionality of lost limb or organ.

2) Cybernetic Appendage: Replaces arm or leg. Increase Brawn or Agility by 1.

3) Cybernetic Implant: Choose 1 General skill. The cybernetic provides one rank in that skill.

#2 & #3 give the character some type of boost to stats. Does #1 provide any stat boost, or only added narrative to your character.

I was hoping to craft a cybernetic that gave access to a talent. Can I do that?

The mechanical benefits of #1 is if you lost a limb or organ, you can get a prosthetic. Critical injuries can cause such a problem.

As for the last question, let me quote Special Modifications p. 74:

"Inspired GMs are encouraged to create their own unique templates -- all a template needs is a Name, Material Price/Rarity, Check, Time, and profile for the result, which GMs can provide to their players as they see fit."

So, if a GM approves or agrees to allow it, you can.

Prosthetic Appendages are just that, prosthetic. Any drawback from missing a limb would be rectified by that. (Think Lukes hand post ESB)

As far as "Talent Cybernetics" go, I once gave a custom eye implant to one of my nemeses that provided him with a rank of the True Aim talent.

As long as it's not something outrageous and is within the limits of what makes sense, I would be open to suggestions if my PCs wanted something specific.

So as Blackbird said, it's probably best to bring it up to your GM.

I am AFB but if I remeber correctly you can use and to add a bonuses to skills.

But I don´t think special Talents weren mentioned, but whatever the GM allows is ok,

At my table a Player would have to use a and provide a very good explanation why this talent should be added to the artifical limb...

as for your #1 that´s just a replacement (and therefore much cheaper then the others) so even a char that got his hand cut of (happens quite often by the way) isn´t a total mess (except him beeing a Lannik... then he wouldn´t replace it... strange code of honor those little twerps)