If I may make a few points in regards to your post please IceQueen...
I would shy away from defining different 'species' or 'races' of vampires, as we are all human at a basic level. But would instead say that there are different methods of energy exchange/absorbtion which define a cultural difference.
I feel personally that we are all born with the potential if it is in our soul, but that indeed, certain events need to occur in our lives (or past/future lives) to bring us to a 'turning' point of conceptual understanding of what a vampire is. The awakening is more of an ongoing process, a self-discovering trip through oneself, as there is always something new to learn.
As to immortality, there is a lot of 'discussion' and disagreement as to what this means. The most common ground is that it is not the physical shell which lives forever, but the immortal soul which is able to divulge the information and understandings of previous lives into the current one, thus giving the wisdom of ages and allowing the conciousness to hold together through many lives, though, some say that this enables a longevity of life through better undertsanding of energy works upon the body.
garlic, silver, holy relics and water I don't beleive can harm anyone unless the person being attacked with them has a psychological condition or indeed, rare allergy, but sunlight will kill anyone that spends enough time in it and it is hot enough, so people are affected to varying degrees and as the system of a vamp is designed to absorb energy, this can lead to 'overload'.
The term hybrid is a little unfair, as all are individuals and unique, so all would be referred to as hybrid, just as all human races are 'hybrid' due to genetic mingling. Once one starts own this road, racism and superiority complexes start to develop and so I avoid this or any other similar term.
'Master Vampires'? Who knows, not me...
'Half Vampires' can be equated to what is known as 'sympathetic vampirism'- a condition where the energy system of a non-vampyric person is damaged in some way, usually through psychic attack or a feeding that took too much and/or too regularly, resulting in acute energy loss that needs to be replenished in a feeding manner, but this can be repaired, whereas a true vampyric neccessity will never heal, even over the course of many lifetimes.
The servile thing is too true...but this can be acheived by any competant and malevolent psychic being. If one chooses to submit to a vamp for their own pleasure, so be it, but there are cases of 'ridings', where an entity will attach itself to a person and essentially 'pull strings' in order to generate its favourite flavour of emotion, be it through sex or violence or any other act. This can be broken through careful meditation and/or sheilding though.
