All of the above are possible, and in fact plausible.

The most likely answer is actually your final one, in that the doctors designing the new life-form (because that is essentially what they are doing) would choose which traits were important from each parent. There may be compatibility restrictions though that mean they they are forced into choosing one in particular of the first three instances. As the person designing the universe you could choose those constraints though, so if you want a certain option but don't know why they would choose it then they could be forced to make that choice for biological compatibility.

Note that alien->human telepathy is highly unlikely from a reality-check perspective unless the human has some augmentations (for example implants) to support it.

All of the above are possible, and in fact plausible.

The most likely answer is actually your final one, in that the doctors designing the new life-form (because that is essentially what they are doing) would choose which traits were important from each parent. There may be compatibility restrictions though that mean they they are forced into choosing one in particular of the first three instances. As the person designing the universe you could choose those constraints, so if you want a certain option but don't know why they would choose it then they could be forced to make that choice for biological compatibility.

Note that alien->human telepathy is highly unlikely from a reality-check perspective unless the human has some augmentations (for example implants) to support it.