1. I agree that you could possibly be harmed when you cast a spell.
2. I agree you should know what the spell could possibly result in.
3. I do not agree it is always dangerous no matter how safe it sounds. If you understand how to cast a spell and research all you can on that spell, you can be perfectly safe about casting it.
4. Karma is a reality and sometimes it hurts a lot! I am so sorry that the world can be so uncool.
As for other rules, there are no rules to magic, but there are some laws. These laws can be bent but not broken.
Always consi. I have to disagree. I believe what you send out (energy) comes back to you three times the magnitude of what you sent out, good or bad. So if its bad yea, your pretty much screwed. But if you do good, then you have not a thing to worry about.
Consequences are not always negative, sometime the consequence of our actions is a positive thing. A spell backfiring is also not a bad thing either. I have found that most of the time if a spell backfires it is really just the gods teaching us a lesson. :)
Most spells just backfire strangly and instead to an ironical adjustment, doing the opposite of what was expected.
For example, a luck spells; the worst case scenario is having bad luck for a while. Attempting to kill somebody; the worst case scenario is you dying instead. Protection/veils/forcefields/etc. for you or your friend(s); evil is brought to you.
It really depends on the spell; not all spells hurt you. In fact, some don't even backfire, they could just simply not work.
This all ties into take responsiblity for your actions. I strongly believe that witches should be prepared to deal with consequences, good or bad. If you spell backfires or does not work either you did not cast it correctly or the universe has simply denied your request. The universe can be worse than a lawyar when it comes to your spells.
I agree with you batmanfallen. No matter how safe the spell sounds, it also dangerous. No matter how you focus, no matter how good are you in magick, there WILL be accident.