Problems 1 + 3 are bugs with Zen Lightbox. I'm working on fixes for these atm.

Problem 2 can easily be resolved by the following...

1 - Login to your admin (for Zen Cart)
2 - Click on 'Catalog'
3 - Click on 'Product Types'
4 - Select the product type you wish to edit (the default will be 'Product - General and will already be selected)
5 - Click on the 'Edit Layout' button
6 - Change 'Show Manufacturer' to 'False'

Nice and easy! :)