1. "Applying the death penalty" or "death penalty execution". It's how it's phrased here.

2. The $ goes before the number, along with a comma.

3. We've known the energy cost of murdering people on death row for a while. And I agree. It's ironic, but for me it's ironic that the only reason asshole states are holding off on some death penalty executions is because of the recession. However, there are some (like Texas) that won't give a shit about wasting energy or money.