Maybe is kind of late for me to add something to the topic, but it is still interesting enough to give it a shot.
1) Isn't Satan just a mythical archetype & a reflection of man's inner most desires?
Mithology itself has the quality to transcend all human needs. As put in the book "Pathways to bliss" Joseph Campbell said in a speech that Muslow's pyramid of human needs made him think a little bit when he first saw it and he didn't know why, then after some minutes he realised why. He said that mythological beings transced all of that. Gods are not just archetypes or reflections of men's inner desires, they are beings which not only can reveal our true nature, but transcend all of the Ego's needs (like desire of acceptance, others approval or even time itself).
2) Wouldn't the worshipping of Satan as a real being create dogma just like religions who worship God? Isn't Satanism & Luciferianism antidogmatic?
Not really, it depends also on how rock-headed an individual is, I would say. I would say that worship of Satan or Lucifer has anything to do with dogma, but sometimes you truly find someone to regard others as "untrue" or "profane" for not agreeing with him/her.
3) Why would you feel Satan is real & not an archetype?
First of all, what do you define as real? As it was put earlier thoughts are very real, now try to think of the things within the unconscious mind which transcend the conscious' mind thought. I would say that gods are very real, but not on the scientifical perspective, but rather on a more subjective/intuitive side. Also, seeing it as an archetype is the very basic beginning in understanding how much more than just "fiction" those things are.
4) Why is it that I see such parallels between Lucifer & Christ? (Meaning: Lucifer rebelled against God in Heaven & got tossed out & Christ rebelled against God on Earth & was crucified. )
Maybe there are some similarities between Lucifer and Christ, but I wouldn't say those two have so much in common after all. From what I know, Christ did not rebel against God, he rebelled against the judaic law and tried to give God's message to people in a better articulated manner so God wouldn't choose to say "you know what? people were a mistake, erase them". It might be because I have a Gnostic approach why I see it like this, but with Lucifer, Lucifer is totally different from Jesus. His light is of a very different manner, a type of "infernal light". You can think of Lucifer's light as the light of alchemists, lumen naturae, a light hidden in nature that is not an opposite or different force from darkness, as with that from Jesus or Yahweh (referred to it also as the thoughtful light of creation), but rather the light of enlightenment. This kind of light appears when one resists the natural instinct of running away from darkness, and out of its intrisic strength and value, darkness lights itself up in a very paradoxical thing, the "black light" or the thoughtless light of the Divine, as referred to by the Gnostic Satanists.