Mass Product Actions

Yes, you can add a product to several categories. For this, you need to disable showing categories as tree. Read on to see the screenshot. 

Yes, using the 'update attributes' action you can remove or replace a website for a number of products in bulk. To see a step-by-step guide follow the link below. 

Any attribute including meta title/description can be changed in bulk with the use of the Mass Product Actions extension. You can make it using the update attributes action. Read on to see the screenshot.  

If you need to change an attribute set, it's possible with Mass Product Actions extension. For this, you need to make changes right on the Manage Products grid. Read on to get compete instructions. 

Yes, you can add cross- and up-sells as well as related products using a multi way algorithm. Go on reading to see the screenshot.