I am making the desert table for my BIL Bar Mitzvah and have a question.
How far in advance can I make the cookies? it's in 2 weeks and I have tons to do. Can I make them now and freeze them, or will the taste be bad?

As long as you store them correctly, there will be no difference in taste. I usually freeze the cookies undecorated, though many have good luck freezing them fully decorated. I place the cookies in a freezer zip-lock and suck out all the air, using a straw. To protect against breakage, place them in containers and then into the freezer.