In answer to the question
can a white man be rasta? Any Person can be a Rasta, if they want to be, that's if they feel the livity and with that Overstanding, they live a conscious and wholesome life experience, why shouldn't they? Indeed the capacity to be righteous (Positive/Good), or unrighteous (Negative/Wicked), isn't based upon race or gender, or least it shouldn't be. It should be based on your works and actions, Indeed the whole notion of a chosen race is just propaganda that was spread by those agents of the system as they went about their process of divide and conquer on behalf of their masters. Using one's inherent critical faculties, ask your self the following question;
Why would the Universal All knowing Consciousness decide to treat one set of people different to another? By using you intelligence you would soon arrive at the conclusion that
It Wouldn't The reasoning supplied by those in control is merely based upon foolishness, that in all honesty can only have emanated from a perverse and subjective mind. However, due to the brainwashing programme that has been deeply instilled in the vast majority, by centuries of violence and mis-education, by the system, people actually believe that the nonsense they are told, to be the truth (the word of god

) and are therefore willing to carry out atrocities based on that kind of programming.
Indeed there is a world of difference between RASTAFARI; the Precursor to the knowledge of Universal Overstanding) and Rastafari the little religious doctrine based style/cult that some expound as an alternative to established religion. Anyway I'm starting to digress, so let's get back to the topic;
Another point that should be made regarding who can be Rasta, is that there is no one way to live the
experience in terms of the material existence, i.e A Rasta residing let's say in Bronx USA, Manchester UK or Amsterdam in the Netherlands; will each have a different material existence compared to a Ras living somewhere hot (like JA, Trinidad or Gambia) and as such, some of the reasoning and indeed the livity may alter accordingly.
However, one aspect that resonates with all Rastafarians is H.I.M Selassie I, (albeit in differing levels of perceptions and perspectives) Some of the I, will tell you he is the living JAH (God), Whilst others will tell you that he is a returned Messiah, or a next set will even reason that he is simply a great King and a Symbol for Africans, in other-words, whatever, and however they feel that their perspective on the Universal Consciousness manifests itself within them.
However, to some; Rastafari is a concept, a way of life that is greater than simply a individual (even if that individual is the physical manifestation that embodies the principle that they adhere to) Indeed the concept/(way of life) is merely the pathway to the higher consciousness that lies beyond the physical realm, but yet is universal in its infinity. The religion that some attach to the way of life is neither here or there, in the scheme of things, because the great truth lies with in each of us and is waiting to express itself.
So let the reasoning really start;