This is a thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. The previous "stupid" questions thread is at almost 500 questions in about a month, so I think it's time for a new one.
Also, I have a new "stupid" question.
Yes. You do lose energy moving light uphill, even if you have perfect emitters and collectors.
I don't think you can do that. Photons have no electric charge.