Satan Good Or Bad, ?????? Options

Is satan (Lucifer) really evil i mean if you follow christian beliefs. I know he is supposed to be the most evil being/deity ever. But what happened to the souls of those who were bad before Lucifer became the devil i mean once he was Gods highest regarded angel. So is it to be assumed that every one was just perfect before satan come around. Or was God just scared that Lucifer was becoming more powerful or just as powerful and decided that he wanted to remain supreme. So he banished Satan was god just being power hungry and didnt want to share his rule? Anyone have any thoughts on this i do not believe in christ or any of that personally but i do like to know as much as possible so when people (general people in my area are christian) question what i belive i can put it to them so to say. (IMG:style_emoticons/default/sport_boxing.gif)

Thank you thoth for the post it was very informative and apreciate you going in detail with each of my questions. I do not really care to much in what other people think of my beliefs its just annoying when there like OH NO your evil which in fact i am not at all and for example i was laying in the hospital almost dead and they had a christian preacher come in there and bug the shit out of me syaing have you excpeted jesus me trying to be nice said no in a calm tone she took it as an invitation to put her hand on were i was hurting and pray for me then i got a lecture on how the bible is just the best thing ever i wanted so bad to just tell her how damn wrong she was and scream at her but i held my tongue being kind person i am shew very annoying though :/. LOL thats kinda a story of something that happened to me but again i appreciate the post. (IMG:style_emoticons/default/smile.gif)