Wordpress MU (Paulae and others)

Hello to anyone that uses WP MU. After a couple of weeks struggling with Drupal (test site works great but the live site is borken) I am going to try and give WP a chance to fill my needs. Just a few questions as to the usabilty of WP MU?

The site will provide a community for those invovled in strength training in the UK and a shop. I moved to Drupal for Ubercart and the various addons for creating a social networking site. They work great on my test site, but for the life of me I can't get the live site to work.

I am happy to keep the shop simple as initially products will be limited. For the social networking aspect I just had a look at WP MU. I persume that users can have specific permissions set as to where they can start a blog, and that I can have a central main site that people have to come to first before they go to others blogs.

So basically I have the main site with recently updated blogs in a side widget - and blogs searchable by category. Would it be possible with that to have a widget (say latest shop products) displayed on every blog?

Thanks in advance,

John