Do the wheels of taxi-capable helicopters have power? There are many big helicopters which seem to taxi just as good as any fixed wing aircraft, for example CH-47.

Do their landing gear wheels have power or they also taxi using thrust like their fixed wing counterparts?

If they do have power, are the taxi controls different from the standard controls?
The wheels do not have power - there is no propulsion system linked to the wheels, they just spin freely.

Taxiing is achieved by adding just enough collective so that the helicopter starts moving, but not enough to lift it off the ground. A little forward cyclic also help.

To slow down, the main wheels have brakes, like fixed-wing aircraft.