I dislike the removal of Mist Energy and the cost of using Elevators. Energy has a big role in the SK world.
The Energy is one of the main things in SK, removing Mist and the cost of elevators will bring it down.
And if the players wouldn't need to use Energy anymore, the story wouldn't be right.

Lore

Shortly after the Spiral Knights landed upon Cradle, scouting teams reported an intense energy signal coming from the planet's core, and now the knights have been tasked with investigating it in the hopes that this energy can be used to power their ship.
The Clockworks and nearly every machine the knights encounter run on energy, including the Spiral Knights' own power armor. All knight armor is equipped with a tank that pulls airborne energy—known as mist energy—into their armor, allowing them to function and power up machinery they encounter. However, mist energy dissipates almost as quickly as it is acquired, and thus it can never be permanently stored.
A form of energy, known as crystal energy, is also available to circumvent the downfalls of mist energy. Unlike mist energy, it can be stored safely in large amounts in a knight's reserve tank because it does not decay. The Strangers that run Haven mine areas of the Clockworks for the crystallized form. Like everything in their possession, it is available for sale.

(From SK Wiki)

Edit: Please keep discussion and feedback about the upcoming release announcement in the discussion thread. Thank you!