Customize Multiple magento webshop a bit

I've a multiple magento webshop (3 shops in dutch, 1 in english, 1 in french and 1 in german) that I'd like to customize a bit: - The invoices of the three dutch shops are now all the same, because I can only change the invoices and orders per language now. I'd like them to have 3 different logos and stuff - The three dutch shops have to have different category ordering. For example, in shop 1 it's menu is now like this: 1, 2, 3, 4, 5, 6, 7. In shop 2 I'd like to have 3,4,1,2,7,5,6 and in shop 3: 1,2,3,4,7,6,5. Something like that. Now that's unpossible because when I change something in categories I change it for all webshops. - Fasten up the speed of order process. It's a bit too slow, which costs conversions. I'd like to know why that is and how to solve it.