Hello, i hope i'm in the right place for asking that;

Is there a legal notice of what can be done or not in the world of 3d modeling of real objects, for free, for selling ?

I think we cannot propose a T shirt in a store with a famous sports wear logo on it. For design, i suppose we cannot sell a copy of a real product / car / fridge etc ? I'm not really sure where the prejudice is as it's free advertising, but they own the rights, so i can't. Is this right ?
Can i sell a morph of la femme who makes her like a real famous people ? I believe no.

thanks you for links, advices...