Command line interface to Movable Type blog (Net::Blogger)

After looking for quite some time and trying to understand the Movable Type API and very likely not understanding everything, maybe not even much (here is the route which got me nowhere: all XML-RPC links on Movable Type's API  redirect to Typepad's developer site. Nothing here did help, not the JSON stuff nor the scrpting libraries. Since I know Python and PHP only very little I focused on the Perl stuff, especially looking into Perl packages like JSON::RPC, RPC::JSON, RPC::XML etc.but couldn't get a grip how to get something in or out of the blog).
Finally I found an example on the internet which was using Net::Blogger with Movable Type's mt-xmlrpc.cgi so I went for Net::Blogger, an admittedly old (2006?) package relying on (what I found out during the installation) other old and partially deprecated packages like Error but in the end it worked.

Installation
Since all was done on my Ubuntu system I first needed to get my Perl installation there in shape. I hadn't done this for a while but it worked as memorized:

• start cpan in a terminal window and follow the instructions
• run install CPAN to get an up-to-date version
• run install Net::Blogger and let CPAN also download and install the necessary dependent packages

This took a while and there were also some hickups (which I unfortunately forgot so I can't describe them here and tell people how to circumvent them, sorry) but finally the packages got installed and Net::Blogger is available for me.

Example program
Here is an example Perl script which creates a simple blog entry.
It accesses the mt-xmlrpc.cgi script as outlined in the code, you need your username, your blog id (it is listed e.g. in Tools->Import) and your web services password (you can find it in your profile), the assumption is of course that you own the blog or have at least write permissions. Blogging is again a two step process: first you create the blog and secondly you publish it.

use strict;

use Net::Blogger;

# Your blog provider's path to MT scripts
# (assuming a standard installation of MT)
my $url    = "http://blogs.zzz.com/cgi-bin/mt";
my $proxy  = $url . "/mt-xmlrpc.cgi";

# My credentials
my $user   = "xxx.yyy\@zzz.com";         # Your blog username
my $blogId = 20421;                    # The blog id of your blog

# Create blogger object
my $mt = Net::Blogger->new(engine=>"movabletype");
$mt->Proxy($proxy);

# ... and add my credentials
$mt->Username($user);
$mt->Password("xxxxxxxx");      # Enter your web services password here
$mt->BlogId($blogId);

# Create blog entry
my $entry = $mt->newPost(postbody=>\"<B>hello</B> world") 
   or die "[err] ", $mt->LastError( ), "\n";

# Publish blog entry
my $pub_entry = $mt->metaWeblog()->newPost(
   title=>"hello",
   description=>"world",
   publish=>1,
   );

This is nice for creating a blog entry from the command line, one could use a more polished version which e.g. would take the blog text from a file etc.
What is not clear to me yet: how to add tags to the blog and how to assign proper categories (not sure if this is possible via this interface).

And now?
But after having achieved all of this I want more: I would like to migrate a blog entry from somewhere else with not just the blog text but also attributes like original blog date, files or attachments (called assets in Movable Type speak) of the original blog, tags, categories, comments. This can be achieved via Movable Type's import (maybe not the assets piece, not sure) so I really need a command line import interface, not just a command line blog creation interface.