I am trying to use this - Chef Stefs southern red velvet cake - recipe from the database for a friend who requested a red velvet cake. I do not have buttermilk and I red somewhere that using milk and lemon/vinegar, messes with the consistancy of the cake. Is this true or will this cake work fine doing that?

It will work fine, put 1 TB of vinegar or lemon juice in the bottom of a glass measuring cup, then fill with milk up to 1C. Let stand for 5 minutes, you have buttermilk!