So are we allowed to build anywhere outside the city as long as it doesn't grief others, and we are prepared to handle griefing on our own?
Yup. We will reactively deal with griefing/general poor play outside the walls if people come to us about it, but it's not something we're able to pursue proactively.
So if griefing is allowed outside the walls does that mean somebody could attack me if I were wandering around outside the walls?
Not allowed. As above, this will be reactively moderated.
What's the status of archiving the old map? Is it available for download yet, and if not, will the link be posted in this topic?
That's on Wampbit, whose computer is fried just now. The link will be posted up in this thread (and ideally in the OP too) when it's uploaded.