Are Might, EnergyCost and PowerCost a trait?

Yes, Might, Energy Cost, and Power Cost are considered traits of a game object.

According to Rule 454.3.a, these three values are specifically categorized as traits that are subject to arithmetic modification (the third layer of effect application):

"454.3.a. This layer deals with the mathematics of increasing and decreasing the numeric values of the traits of Game Objects.

• Might
• Energy Cost
• Power Cost"

Additionally, Rule 454.1.a.1 notes that the assignment of Might is handled within the first layer (Trait-Altering Effects), further confirming its status as a trait.