Hi Mikhael!
I'd like to comment on something bats said, and no disrespect intended toward you at all bats, okay?
Shamanism may be a calling but I don't believe it is any more so than any other such as Empathy, Telepathy, Clairvoyance, or whatever. A person's 'calling' seems to me to be a matter of personal
inclination; not in the sense of actually making a conscious decision but more along the lines of a person's disposition. This disposition may or may not be a product of the environment the person is exposed to in this lifetime. Personally I believe the stronger influence is that of past lifetimes. Who we are always seems to end up being who we
were in the past if you look at it from the viewpoint of our paths extending over many lifetimes as a continual growth process.
In that regard, yes, you may have physical and/or mental problems if you radically deviate from the path but this would be more like a natural reaction or 'punishment' you bring on yourself rather than a punishment by some deity. An example would be if you ate something that was toxic, poisonous, or otherwise disagreeable to your system. You naturally are going to get sick or suffer other adverse effects, right? Same thing here, or at least that's my opinion. This is why so many people seem to be unhappy or feel something is missing in their lives. What they're missing is the path they truly Need to be on.
I follow a Shaman's path and can honestly say I never experienced any kind of illness prior to turning specifically onto this path. Perhaps because I was always on it anyway...
But I digress.
Anyway, I started out following a Stone Shaman's path but as my learning and understanding grew I quickly expanded my scope. The larger scope of Shamanism deals not with individual deities but universal energy-hence the four Elements of Earth, Air, Fire, and Water. This energy exists in all things (Yes, you can think of it as The Force if you want. It doesn't really matter.). The wellspring of this energy is The Divine, The Creator, The Creative Forces, God, Goddess, or Supreme Deity-whatever you choose to call it. This is where all the power and strength of Magic comes from and this same energy is available to both humans and other deities. As a Creative energy its 'polarization' is Positive, not Negative. Shaman's look at magic as the transformation of this energy to bring about change. They may call directly upon this universal energy or they made seek assistance from other beings or creatures. As for myself, I call on The Divine but ask The Elements and other animals and/or flora for assistance in the calling.
Again I apologize in differing with my friend Bats but there is no strength, special gift, or power in a Shaman beyond their ability to attune with the the Creative Forces. In this respect they do not hold power or strength because they only channel and direct the energy, not hold it or seek to control it (it always ends up that they can't).
Now, this definition may not fit in with the textbooks or popular opinion but it is the path I follow. People may not look at it as a 'true' or 'historically correct' version of Shamanism and I'm okay with that. The work will get done just the same and that's the only thing that counts!
Hope this helped some Mikhael! Bats, sorry if we disagree. No offense intended. Peace and Blessings!
One Walker.