They're not already full members. We are, and have an economy built around that fact. And they're willing to accept freedom of movement when Labour won't even commit to that.
That is a fair point. That Labour is not committed to Freedom of Movement, it doens't make them racist though.
Labour haven't been part of any official negotiations. So we don't know what deal they will strike with the EU. Once we know that then it is proper to take a position on the referendum.
Remember that a Labour Government means a 2nd referendum between a Labour Deal and Remain. Where as a Tory government means we will probably do a hard brexit because Boris Johnson will not negotiate a new deal.