Unfortunately, no, there's no way to claim your OpenID if your LJ account is deleted, even if it's not yet deleted and purged. Part of the OpenID claiming process involves authenticating yourself that you do control the OpenID URL you're trying to claim, and in order to do that, you have to be logged into LJ and your LJ needs to not be deleted. (Deleted accounts don't have the right information in the headers to let OpenID authenticate you.)

I'm afraid I don't know the answer to the disabling-Javascript thing!