Ok, here comes this newbie's first post....

A couple issues:

1)Typo: "walled.dat".

2)There's no protection against MITM attack when you download that LiveCD - people need to ensure that the LiveCD image they download hasn't been trojaned on its way to them.  Checking securely obtained SHA hashes, PGP/GPG keys ... very important and worth mentioning!  Ditto for the bitcoin client.
OP says: "I think it makes sense to trust both the Ubuntu LiveCD as well as the client from bitcoin.org for now."  Well, it makes sense if you ensure they are what you think they are -- you have to trust someone.


-=>MATTTT>--