I, like many players from years past, have been with this game from the first year. Through much effort, and twice as much difficulty, I have managed to collect nearly every achievement in the game, including the ones that are no longer obtainable due to certain changes made in the game.

Instead of completely "removing" them so that no one else could get them, I would suggest changing their requirements so that they're still obtainable for everyone.

Minor Miner: Collect 500 minerals of any type.

Moderate Miner: Collect 1,000 minerals of any type.

Major Miner: Collect 1,500 minerals of any type.

Marvelous Miner: Collect 2,000 minerals of any type.

Master Miner: Collect 2,500 minerals of any type.

Walk It Off: Revive a downed party member with a Spark of Life.

This is just a meager suggestion, but I feel that it would still conform to the concepts of these particular achievements.