QIf a follower's card type is changed to amulet, do effects which target followers apply to it?

ANo. Only effects which target amulets apply to it.

QIf a follower's card type is changed to amulet and then it evolves, does it trigger Mini Soul Devil's "Whenever one of your followers evolves" ability?

ANo. It's an amulet, not a follower, so it doesn't trigger Mini Soul Devil's ability when it evolves.

QIf Mordecai the Duelist's card type is changed to amulet, then it's put into the cemetery, and I put it back onto my field with its Last Words ability, is it still an amulet?

ANo. When a card is moved from the field to a different zone, it's considered to be a new card and loses any effects applied to it when it was on the field.

QIf a follower with Ward has its card type changed to amulet, do enemy followers have to attack it when it's engaged?

ANo. Amulets can't be attacked.

QIf Diamond Master's card type is changed to amulet, do opponents still need to select it when selecting followers for an ability?

ANo. Since Diamond Master is an amulet, it can't be selected when selecting followers. However, if an opponent is selecting cards for an ability like Execution's, which can select amulets, they must select Diamond Master.

QIf a follower's card type is changed to amulet and then it's evolved/raced, do its On Evolve/On Race abilities trigger?

AYes, they do.

QIf a follower's card type is changed to amulet, can it still be served and raced?

AYes. Note that even if raced, it remains an amulet.

QIf a follower's card type is changed to amulet, can it still evolve?

AYes. Note that even if evolved, it remains an amulet.

QIf a follower with a Last Words ability has its card type changed to amulet and is put into the cemetery, does its Last Words ability trigger?

AYes, it does.

QIf a follower's card type is changed to amulet, can its attack and defense values be referenced?

ANo. It still possesses attack and defense values, but you treat the card as if it doesn't have them, and they can't be referenced by abilities.

QIf a follower's card type is changed to amulet, can it attack?

ANo. Amulets can't attack, be attacked, or take damage.

QIf a follower's card type is changed to amulet, does it lose all abilities?

ANo. All its abilities remain valid. This includes activated abilities, evolve abilities, and Last Words abilities.

For example, if you change a Water Fairy's card type to amulet with this follower's ability, it becomes an amulet named Water Fairy with the following three abilities: " : Evolve this follower"; " : Put this card into its owner's cemetery"; and " Put a Fairy token into your EX area." If it gets put into the cemetery, with its new activated ability or otherwise, its Last Words ability triggers as usual.