I only want to clone some things, without changing them.
Is there any way to clone a repository without all the hassle of opening an account, setting up a SSH key, etc?
It's really easy. Use bzr branch lp:PROJECTNAME.
Example (no Launchpad login or keys on this machine):
$ bzr branch lp:bzr
You have not informed bzr of your Launchpad ID, and you must do this to
write to Launchpad or access private data. See "bzr help launchpad-login".
and then it proceeds to download the code.