Anyone who is not a jew is a Pagan; anyone who is not jewish is Pagan. As such, Spiritual Satanism is our (Pagans') actual religion/spirituality.
Black magic is used for justice and punishment; to right wrongs; revenge; etc. That may include, if the mage (practitioner of magic) is so inclined, to curse someone, kill them, whatever. You decide the punishment which fits their offense against you.
You are free to do WHATEVER you wish as a Spiritual Satanist; however:
1) anyone who who opposes Satan will regret it sorely (cursing other SSs, for example, would be not only rather difficult, but not very clever, either), and
2) anyone who is a Pagan should be law-abiding
There will, of course, be consequences or 'prosequences' of your actions. As advanced Pagans - i.e. Spiritual Satanists - we have cheats or loopholes; we can cause misery and suffering to an offender, or give them cancer until they die, if we are so inclined. Perhaps cause them a car crash, or financial/familial ruin. Whatever you wish. Witchcraft/magic is not "illegal", but even if it were, how could it be policed? Using White magic is to manipulate your word around you, so your world is as YOU want it to be. You can also use white magic to help other people, in any manner.
Heaven and hell might be a bit more difficult to understand. Along the Human spine are 7 major Chakras. Briefly, our mortal enemy cut us off from Satan and the Gods, and sealed our Souls at the 2nd Chakra, the Sacral Chakra, which is sexual. Sexual energy is not "wrong" or "evil" or "perverse". In fact, it is extremely important in our survival, not only for reproduction and propagating our own Race. That's why there is always so much emphasis on sexual things, and why doing anything sexual is a "sin" in christianity and islam.
Having been sealed at the 2nd Chakra, our Kundalini is trapped, basically, at the 1st Chakra, the Base Chakra. This, essentially, is 'hell'. One might say we live in a literal 'Hell on Earth'.
'Heaven' is the 7th Chakra, the Crown Chakra, which the Kundalini pierces through, after it travels up the spine through the other Chakras.
You might know a bit or lot about the book of revelation in whichever bible you prefer to have read, which mentions the 7 seals. This is the sealing of our 7 Chakras.
You should visit and go through these -
1) joyofsatan.org
2) exposingchristianity. com
3) groups.yahoo.com/neo/groups/JoSNewsletter/info
4) exposingthelieofislam.wordpress.com