The way this works: Leave a comment, I'll reply to it with an answer, then place the answer into the deviation.
1. Q: "What're the fundamental values all Satanists believe or practice?"
1A: Satanists believe in obtaining godhood/apotheosis through the genetic/spiritual modifications Satan gave to humanity; a process long forgotten and thought of now to be a "myth".
Unlike other belief systems, Satanism actually requires work... instead of sitting around all day playing video games or praying to some god. Godhood is obtained through power meditation, yoga (kundalini/hatha) and hard work, perseverance.
The other values Satanism promotes are knowledge, truth, justice, kindness, self-empowerment: and freedom of the mind, body, and soul.
2. Q: "If it helps, you can divide into the different branches, since I'm not sure what branches really believe. What I just know there's a few of them."
2A: As for "branches", there are no branches of Satanism.
Either a person follows reality, or they are not a Satanist; LaVeyanism is LaVeyanism, Luciferianism is Luciferianism, and Satanism is Satanism.
3. Q: "If you were to place a simple description or definition of Satan, what would that be?"
3A: A bit of a preface: the red "evil horned man look" is NOT AT ALL ACCURATE to how he looks... that is merely how his enemies portray him.
He is a tall blonde humanoid with electric blue eyes: tan-ish, strong jaw, well-built.
Usually I see him wearing a white robe: though sometimes he appears with armor, like a knight. Sometimes he also has ethereal-looking wings.
I've found that the hair length varies when I see him, but he always has the same general look to him.
His aura creates a calming effect, but also raises the atmospheric pressure of whichever building he appears in. I have a drawing of him in the Satanism section of my gallery.
As for describing him non-physically; he's very kind, understanding, supportive. He has never said anything negative to me or about me. He also has a great sense of humor, and knows when to relax. He cares deeply for humanity, and I hope we are reunited with him soon (he has stated to me personally that he is "coming to Earth".)
4. Q: "Could you also give a description of Lilith. I don't know to much about her other than she is a big supporter of women's rights."
4A: Ah, Lilith, Satan's wife; She's a lovely woman.
Strangely my vision of her looked wildly different than the one portrayed on JoS;
Her hair is black and is styled somewhat similar to Asami's (Legend of Korra).
She has violet eyes that show kindness; her skin is a light color. She seems to wear a slight amount of makeup, but nothing too drastic. Of course, she's also very attractive.
5. Q: "How long have you been a Satanist?"
5A: 4 years of being a dedicated Satanist, almost 4 1/2 of being a Satanist. I dedicated April 31st, 2011.
6. Q: "How did you come to Satanism?"
6A: For the first 13 years of my life, 7 or so of those were spent as a christian... the first 5 or so I don't remember much at all. I never really got into christianity. maybe for a week or so, but that's it. I never felt the presence of any of the bullshit book's characters.
Around age 13 I stopped using fluoridated toothpaste, and honestly I think that's what led me to start questioning things (in addition to the "coming of age" thing.)
Age 16 I left christianity after various happenings, and realizing I had never seen any evidence AT ALL for christianity being legitimate... for 4 years I was lost, tried a few "occult" things, but nothing ever stuck with me. Every prayer felt like it was sent to a black hole, not any sort of god or person.
I also stupidly thought I was "possessed" during this time (which I have come to realize was just my own subconscious acting out.)
At age 19 I was introduced to the Joy of Satan website... it was a great awakening; looking at the page made me feel like I had finally found the giant, missing piece of the puzzle I had been desperately trying to assemble in my life. I felt guilty at first, but Satan reassured me that I was "home" now and comforted me; forgave me for being a bit foolish (the whole possession bit), as I didn't know any better.
About a week after that, I stood up to my abusive ex-stepfather; this lead to a chain of events in which I was moved out of the house and lived with the man who introduced me to the JoS site. I performed the dedication ritual about 3 months after that (I had turned 20.)
7. Q: "How old are you?"
7A: Currently 24.
To elaborate: I know Satanists who are 14, 19, 35, 50, etc... the HighPriestess herself is around 55, but she looks 20 due to her spiritual advancement.
Satanism is not "herpderp for rebelz 7th graders" or some trash like many spout off.
8. Q: "What sorts of religious practices do you have? (ie prayer, holidays, and rituals)?"
8A: There are prayers for protection, for aid in endeavors, but these are optional.
Holidays: Yule, Feast of Fire, Beltane, Summer Solstice, Samhain/Halloween, Spring Equinox, Autumn equinox.
Rituals: Standard, giving thanks, destruction rituals, banishing rituals, ritual for cursing the church... lately there have been a lot of rituals for reversing biblical curses made by the enemy.
For more information, visit the pages on each.
9. Q: "What are the values that Satanism holds in high regard?"
9A: Not in any order: Kindness, self-empowerment, freedom, truth, justice, helpfulness, knowledge, thinking, courage, moderation, loving life.
10. Q: "You mentioned an alien war more than once. If the aliens had the technology to wipe humans out, why not do it already?"
10A: They get more use out of us alive than dead. Think The Matrix series. keep in mind the war is still ongoing; it is not over, we merely lose a battle early-on.
11. Q: "Are any foods prohibited from being eaten in Satanism?"
11A: None at all.
Although... Satan recommends staying away from processed food (especially those made with bleached flour), as it is unhealthy... but all in all, nobody is going to ban you from eating a certain food.
I remember the HighPriestess mentioning she regularly picked up energy drinks because she liked the taste; at a certain point in spiritual advancement, nothing negative really effects a person.
Personally... I've found that junk foods really don't taste that great anyhow, after you stop eating them for a while. I have a soda maybe once a month, and the only junk food I really eat is ice cream (made with non-artificial ingredients.) My favorite is Matcha ice cream, for the record.