>1.How long should a role normally be.

Roles do not need to be long to be good, although they can be long. I like roles that tell me something interesting about the character. One way to view a role is to ask yourself "What would a god know about my character without talking to them?" It can be phrased as part of a backstory, but it can also just be an informative list of characteristics and motivations. Any motivations that help clarify your role that would not be apparent from your actions would definitely be in your role.

>2.Is their a certain criteria for roles.

Nope! But the better a framework you give us, the better a story we can help you build from it. Or the better we can help you tear it down. All's fair in love and war.

>3.What is a good way to role-play(because my friends say I
>suck at it).<-- Dont know any other way to ask this.

I'm sorry to say, but if your friends are telling you something you're not seeing yourself, you're not going to have much chance of fixing it. I'm not sure if your friends are to be believed or not, but like they say of any other "problem," recognizing it yourself is the first step to a solution. What I'd recommend is that you not try to ask yourself if someone else thinks what you're doing is good roleplaying but instead go out in the game and look for what you think is good roleplaying. Or look at logs that players have posted. When you find something you think is good, ask yourself what you would have done in the situations you find. Would you have been able to come up with an appropriate response to the situation given your character? What are those players doing that you're currently not doing when you roleplay?

>4.In playing for 2 years am I ready to try an empowered char?

There's only one way to find out. And no, I wouldn't be a good choice for a new empowerment character to try to follow. :-P