Q. Can Kiddush levanah be said indoors by seeing the moon through a window? Does shalom alaychem need to be said to three different people or can it be said to the same person three times? Can it be said over the phone?

A. Two of your questions have already been answered on different occasions in this forum (questions # 576, 329, 586, 587 and 732).
As far as the last question; Can it be said over the phone? Did you mean reciting it for someone else who has no access to a sidur; he is listening over the phone as his friend makes the brocho and wants to comply as “shomea k’eone” one who listens is as if he said it himself. The answer would be no, unless he repeats the words himself.
The reason being that we do not consider words that were converted into electric impulses in a microphone and then regenerated in a speaker, as a Halacha valid utterance. (Igrois Moshe O.H. 2: 108 et. al.)
If you meant taking a picture of the moon on your phone and sending the image to someone who cannot see the moon where he is, the answer would also be no, since our Sages did not establish the brocho when you cannot directly see and have benefit from the light of the moon.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a