I'm do some test and basically that work...

BUT i see right now two problems:
-if you have a lot of product perhaps you exceed the time limit. See this bug of node import: http://drupal.org/node/191197

-You don't be able to map the three dimensions fields. I don't know why... but a really simple workaround is to add your costume CCK field for dimension.

I need some more test to understand how to import taxonomy hierarchies http://drupal.org/node/162474