1) Your baby is so adorable. -> Is a correct sentence but if you say "Your baby is so little" to someone, they probably won't understand that you mean that the baby is cute. In english, "little" only means "little/small/thin(when talking about someone's weight)"
2) Your father's behavior is adorable/lovely in somewhat. -> It is not rude to say that but it's really awkward. If you tell that to someone, they will either think that you literally translated an expression from you native language, or that you're really weird ! In english, you usually don't call men (especially older men) "adorable" or lovely unless you're attracted to them, or they are really old. Instead, you could say "Your father is really nice"
3) This color is really cute/pretty. -> Yes, this is a correct sentence !
4) Those clouds has cute shapes. -> "Those clouds are cute" seems more natural
5) My dog is so pretty/lovely enough to be able to eat him. -> "My dog is so pretty/lovely ('cute' seems more natural) i could eat him !"
6) Your mother has pretty face. -> It is a correct sentence (although you forgot the article : "your mother has A pretty face") and no one will think you are rude for saying this but "Your mother is really pretty/beautiful" sounds much more natural.