Hi there. I don't see where anyone has said that your lack of information in your profiles is a barrier to acceptance in any faction. The only thing that was mentioned to you was by me in the Jedi sign-up thread. That wasn't because of a lack of information, talent, etc. or anything else you perceive to be a flaw (you should've seen my earliest attempts at a profile -- we all get better!), it was because the character didn't fit in the Jedi.
I strongly encourage you to stay, because no one has told you that your lack of detail in the profiles is a problem. The only thing you have to decide is which faction you want to sign up for. The Sith, the Mandalorians, and the Mandalorian Separatist Movement are all different factions. The two different Mandalorian factions, for example, are in a war with one another, and the main Mandalorian faction does not like the Sith. You'll need to choose between them and select the one you want to be part of.
Based on your character's profile, my recommendation would be to sign up for the Sith.
I did ask for a bit more information on the profile, but that was primarily to give me a better idea of what to expect from the char as a Sith. It wasn't to ask for a complete overhaul, just a little bit more background would help me quite a bit.
Let's go point by point through your profile. The best way to know how to add more information is to ask questions about the things you said.
1. "He is aggressive." - How? What brought that on?
2. "He doesn't like loud noises." - Why? What happens if he hears them?
3. "He is a brave warrior" - Do you have an example of where he's shown this? What did he do? What makes him courageous?
4. "he is clever." - How so? What makes him clever? What does he do that's clever?
5. "He becomes 5 times more powerful than he is when he rages." - Why? What happens when he does become more powerful through rage?
6. "Some people say he is one of a kind." - Why? Based on the personality, he doesn't seem that unique. That's not an insult, just an observation.
Now your biography:
1. "His hatred towards other people cannot be explained" - Perhaps it can't be explained by others, but surely there's an explanation, no? Why does he hate people? What made him hate people?
2. "he also killed his father" - Why? What did his father do? Were there any consequences to the murder? What did the character do after he murdered his father?
3. "and his mother escaped" - Did he try to kill his mother too? Did he try to find his mother after she escaped? If so, why couldn't he find her?
4. "This evil Wookiee does not like the races: Human" - Why? What makes him dislike Humans? Did a Human or Humans do something bad to him?
5. "He has also hated other Wookiees" - Why? What makes him dislike other Wookiees? Did other Wookiees do something bad to him?
Answering those questions can help flesh out the profile.