When can I get Haedrig's conversations for the Hassling Haedrig achievement?

The achievement says to "Listen to all of the Blacksmith's conversations."

Because some of these are missable, I'd like to know when Haedrig's conversations first become available and if and when they become unavailable. The Weary Blacksmith seems particularly missable.

Solution 1:

Because some of these are only available after the Blacksmith has been unlocked during A Shattered Crown in act I, you will have to start already completed quests after having unlocked the Blacksmith.

The town becomes inaccessible after you start the objective Find Diablo during The Prime Evil in Act IV and so any not heard by that point have been entirely missed.

Act I

New Tristram: Available after accepting the quest The Fallen Star by starting Act I until you accept the quest The Legacy of Cain.
Cain's Disappearance: Available during the quest The Legacy of Cain.
The Weary Blacksmith: Available from the time after you complete the quest The Legacy of Cain and before you accept the quest A Shattered Crown until you accept the quest A Shattered Crown. NOTE: At the end of the Legacy of Cain mission. You must go talk to Haedrig where he stands near "Radak the Fence" AFTER you talk to Leah, but BEFORE you talk to Cain. If you talk to Cain first you will automatically accept the A Shattered Crown mission and will miss the opportunity to have this conversation with him. It is easy to blow right by this one.
Haedrig's Grandfather: Available after accepting the quest A Shattered Crown until you are given the objective Find Diablo during the quest The Prime Evil in Act IV.
Mira Eamon: Available from the time after you complete the quest A Shattered Crown and before you accept the quest Reign of the Black King until you begin Act II.
Haedrig's Father: Available from the time after you complete the quest The Broken Blade and before you accept the quest The Doom in Wortham until you are given the objective Find Diablo during the quest The Prime Evil in Act IV.
Fate of Haedrig's Father: Available after accepting the quest Return to New Tristram until you begin Act IV.

Act II

Returning to Caldeum: Available after accepting the quest Shadows in the Desert until you begin Act III.
Changes in the City: Available after accepting the quest The Road to Alcarnus until you begin Act III.
Meeting Mira: Available from the time after you complete the quest City of Blood and before you accept the quest A Royal Audience until you begin Act III.
About Mira: Available from the time after you complete the quest Unexpected Allies and before you accept the quest Betrayer of the Horadrim until you are given the objective Find Diablo during the quest The Prime Evil in Act IV.
The Vecin: Available from the time after you complete the quest Betrayer of the Horadrim and before you accept the quest Blood and Sand until you are given the objective Find Diablo during the quest The Prime Evil in Act IV.
Going to Tristram: Available after accepting the quest The Black Soulstone until you are given the objective Find Diablo during the quest The Prime Evil in Act IV.
Caldeum After Belial: Available from when you are given the objective Talk to Tyreal at the Hidden Camp during the quest Lord of Lies until you begin Act IV.

Act III

Bastion's Keep: Available from the time after you begin Act III and before you accept the quest The Siege of Bastion's Keep until you begin Act IV.
The Future: Available during the quest The Siege of Bastion's Keep.
Raising the Catapults: Available during the quest Turning the Tide.
The Final Goal: Available during the quest Tremors in the Stone.
Tide of Battle: Available during the quest Machines of War.
Nerves: Available after accepting the quest Siegebreaker until you begin Act IV.
Haedrig's Sorrow: Available from when you are given the objective Enter the Portal to Heaven during the quest Heart of Sin until you are given the objective Find Diablo during the quest The Prime Evil in Act IV.

Act IV

An Apology: Available from when you are given the objective Return to the Garden of Hope 1st Tier during the quest The Light of Hope until you are given the objective Find Diablo during the quest The Prime Evil.