Certainly one of the scholors could give better answers than mine, as a uneducated layperson.
Till one appears maybe my partial answers will suffice.
My source of handy reference is liberation through hearing refered to in its total form as the Tibetan book of the dead. Many prints are available.
I use the Gyurme Dorje translation.
One will attain liberation if ones awareness exits the crown fontanelle, Through this exit the consciousness departs to the pure realm of the skyfarers.
Eyes--universal monarch, left nostril-- unimpaired human body, right nostril--yaksa, ears--god of the world system of form, god of the world system of desire--navel, animal--urethra, anguished spirit--sexual passage, hell being--rectum...that generally is found in page 214 of that text.
One lies on the right side or in meditational posture and by hand and other position blocks all the passages one can. One may also visualize a sacred syllable to rest in all intended to be blocked places.
Where the body heat leaves first may indicate the rebirth. Hot head good hot feet cold head not good. Right side calms the excitable to desire passages ways of the body. ONe should sleep on this side as well.
Soul infers permenance by most commonly defined terms in english. So I would say the term may approximate somes defination of soul but is not generally used as it infers a permenant quality to soul or mind which it does not posess.
HHDL if considered as a representative of tibetan thought on the issue generally does not use the term soul in his published writings. Some american authors like Robert Thurman do.
A continum of consciousness is for all intents and purposes permenant but that is not as soul is commonly defined.
There are various powahs to enable consciousness transference of varying places depending upon ones anticipated spiritual progress or best area of progress. The preferred place being the Buddha body of reality, then buddha body of perfect resource, then Buddha body of emanation. A ordinary person may hope to go to such places but will most likely be liberated from inferior existances only.
The eighth consciousness is called the all base consciousness which is composed of two parts, the all base that seizes karmic imprints and the all base of complete ripening. A reference for this is Everyday Consciousness and Buddha Awakening by Khenchen Thranbgu Rinpoche.
IN the process of death it appears in relationship to drops. Various appearences present depending upon the locations of the drops. In the final stage which has the mind of clear light presenting the white and red drops dissolve into the indestructible frop at the heart. For normal peoples this subtlest level of mind presentation is the moment of death. A reference for this is Advice on Dying by HHDL.
I think of consciousness as resideing perhaps in relationship to the internal drops but actually don't think of the parts of consciousness resideing in different places. There are some say 2 sets of 4 drops each. They work together to create different states of consciousness. Each drop contains two potencies pure and impure.The material drops are supports only as our body supports our mind.
Just a layperson and a uneducated view, and a partial explaination, but reading those references will tell you about it if that is your interest. All are commonly available.
It's probably best to read each.
A successful powah will leave bodily evidence in a dead person. Signs such as blood or emissions from certain places can be fortituous or negative.
Very generally any thing at or about the crown fonatanell is a very good sign.
Those practicing Powah will occasionally have a temporary weakening of the skull at that spot. Some say to much practice of certain powahs and one can weaken ones lifespan.
I'm certain there exists variance to a degree in this thing as described depending upon school and level of training.
"This order considers that progress can be achieved more rapidly during a single month of self-transformation through terrifying conditions in rough terrain and in "the abode of harmful forces" than through meditating for a period of three years in towns and monasteries"....Takpo Tashi Namgyal.