Yes. Some alien races have multiple heads. But currently, it is unknown.
In my opinion, yes. Some alien races have peculiar-shaped heads.
If there are alien races they indeed might have multiple ears.
Yes. Some alien races have multiple hearts. But currently, it is unknown.
Yes. Some alien races have multiple legs. But currently, it is unknown.
Yes. Some alien have hand-shaped heads.
We have not yet met any alien races. However on television and movies, ridged heads are sometimes used for alien races such as Klingons and Cardassians.
Since no one has proof of alien life is is hard to know if some alien races have multiple mouths.
No one can know for sure if alien races have multiple eyes, but it is possible.
In my opinion, yes. Some alien races have supernumerary body parts (i.e. multiple heads, arms, legs, fingers and toes, etc.). But currently, it is unknown.
Yes. Some alien races have multiple fingers and/or toes. But currently, it is unknown.
There is no way to know if any alien races have multiple breasts. There is no proof that alien life exists.
Multiple nostrils would allow alien races to breathe better, so it is possible.