Hello
Ok, i solved the first problem...
1 - Creating a CSV file downloaded from prestashop import function
2 - Filling it with data, and import products using the options use reference as key and force all reference numbers
3 - Creat another CSV with a Reference# field and the other fields that i need to update, fill it with the changed, import it using the options use reference as key and force all reference numbers.
And "it just works"...
The second problem (the product TAG´s are imported but not activated until i save the products in the prestashop backoffice) still persists, it might be a bug, maybe i need to report it in another thread!!!
Best Regards