Logically you should put the skill you get the bonus with in the modifiers for the talent, however
- if you add +1 Melee to you Hammer Fighter talent, you get +1 to all melee attacks, with any weapon even unarmed, when it should only apply to blunt weapons.
- if you apply the +1 as a skill bonus in the weapon properties it applies correctly and only to the weapon, however it applies to all actions with that weapon, attack, parry, shove and disarm. I'm not sure this is the intended behaviour of the talent, though I may be wrong.
- If you apply the +1 as a roll modifier to Melee in the weapon properties it also applies the +1 to Parry, Disarm, Shove, and to attacks with other weapons even unarmed.
Similarly with Defender's +1 to Parry there is a problem with how to apply the bonus
- If I apply the bonus +1 to Parry in the Defender Talent, it applies to Parrying attempts with weapons, but not with shields.
- If I try and add the bonus into the shield as a roll modifier to Melee, it applies the bonus everywhere except to the shield (other weapons and unarmed, and to parry, shove, grapple and disarm)
- If I try adding a +1 Parry Bonus to my shield it's closer, in that it only applies to parries, not attacks, except that the bonus only applies to weapon parries, not shield parries
Ideally you should be able to add the bonus to the talent. Hammer Fighters bonus would only apply to the use of a weapon with the Blunt property, and Defenders would apply to any parrying attempt with any weapon or shield. Only potential pitfall I've come across so far is that the Talent Shield Fighter allows for a slash attack with a shield, so you need some way on the sheet to differentiate between shield Attack rolls and shield Parry rolls (something like the different attack options next to a weapon entry, ideally only activated if you have the right talent).
In the meantime the only way I can see of applying the correct modifier is to have players do it manually every time, which is a little harsh as they are likely to forget quite often.