Answar for ereditation template's modifics
 

how can I make yes that if I create a style, it of it inherits the modifications from an other?
And sorry for mybad English,but I am Italian :S

If you create a child of a style that has the modifications, then that child will inherit all the templates from that style (called the parent style). If you the modify a template in the child style, however, it will no longer inherit that particular template from it's parent.

I see, but if I want to make to inherit the modifications to the templates to a style XML?

If you have a parent style and you modify a template for a modification, then the child style will inherit those templates. Just don't modify the same templates in the child style of the modifications in the template won't get inherited any longer.

Try this out and you will see.