My question involves juvenile law in the State of: kansas

I will try to make this as brief as possible.

15 yr old was accused of abusing his step sister at his Dad's home. The stepsister has a history of picking fights with my son and also telling lies to get her brother and my son in trouble. So the abuse was then reported to child protective services by the stepmother. investigator came and spoke with 15 yr old son - alone with no parent present. a confession of something was made. the son says he was read his miranda rights but he was never arrested. The son is not at a maturity level to understand the full impact of what the investigator was saying and doing. since then it has been coming out that what I was told happened, which came directly from the stepmother, to me about all this abuse were lies with only a kernel of truth. The truth wasnt anything that family members couldn't have dealt with together without involving anyone else. Because of lies the son now has charges pending, court case, attorney and everything.

It's torn the family apart and I as the mother am in real torment.

The court appointed attorney is trying to get the charges down to battery. What does this mean? What are the long term effects of that?
Why wouldnt the attorney go after the lying stepmother and stepsister.
Why not fight this and let the TRUTH come out!
Will us as parents have to pay the attorney's fees for all this?
If he was spoken to alone why wouldnt the attorney get this thrown out?
Is my son truly looking at jail time?
Will this affect him the rest of his life when it really wasn't anything major but b/c of lies told that makes it appear much worse?
Will the courts see through the lies?
Now the grandmother, my mother, has decided she wants guardianship of my son and the attorney thinks it's a good idea! It's not a good idea and something I won't go for.
I'm petrified over it all.

I know I'm throwing a lot out there. I'm just at my wits end. My son is suffering and depressed. This is just so much to deal with and it's really ruined family relations.