Excuse me, I would like to use that power outlet. Could you step out of the way please?
You wouldn't really use any version of the future tense when speaking to the person blocking the outlet.
In the second example, if the week hasn't finished yet, then it makes sense to day "No, he's working (this week)". However, if he has been working until the time of the question, but perhaps won't be working the rest of the week, then you might be able to say:
"Well, he has been working but I don't know if he still is."
"He has been working up until now but I'm not sure about the rest of the week."