Adding products to multishop, how is best?

[vansrv7]

I'm setting up a multishop installation with 3 shops.

I'm going to load products and categories, but it's still not clear to me how PS exactly works and how is better to proceed...I made a few tests but I'd like to have a feedback from more experienced users.

 

I explain:

 

Many products are exclusive for a single shop, so I can add them selecting the appropriate shop;

A few other are sold on 2 shops so, maybe, is better to create them selecting "all shops" in the multishop dropdown and then deactivate the product for the shop in wich is not sold..

 

Or there is a better way to do it? Is it possible to share a product created for a single shop also with others if I change my mind?

 

I have some doubts also with categories: is it better to create all the categories under a common "Home" category even if on each shop the category tree is different?