If my Fidough was damaged, and I evolve it to Dachsbun ex and use the "Time to Chow Down" Ability, does that Dachsbun ex also get healed of all damage?
Yes.




×2Time to Chow Down
When you play this Pokémon from your hand to evolve 1 of your Pokémon during your turn, you may heal all damage from each of your Evolution Pokémon. If you healed any damage in this way, discard all Energy from those Pokémon.

Wonder ShineYour opponent's Active Pokémon is now Confused.
Pokémon ex rule
When your Pokémon ex is Knocked Out, your opponent takes 2 Prize cards.
If my Fidough was damaged, and I evolve it to Dachsbun ex and use the "Time to Chow Down" Ability, does that Dachsbun ex also get healed of all damage?
Yes.
If I use Dachsbun ex's "Time to Chow Down" Ability, can I choose which of my Evolution Pokemon to heal so I don't have to discard Energy from one of them that has just one damage counter on it?
No, you choose to use the Ability or not. Once you choose to use it, you have to heal all of your Evolution Pokemon and discard Energy from all of them that were healed.