No, autistic children don't claim they can see glowing shafts of light, that has nothing to do with autism. Visual hallucinations suggest a mental health issue.
No - autism is a neurological condition, autistic children grow-up into autistic adults.
No, it's not rare at all. CDC put diagnosis of autism in children at 1 in 68 at the moment, so in theory at least 1 in every 68 children is autistic. You likely see autistic children all the time, you just don't always realise that they're autistic as autism is an 'invisable' disability.
No, not all Autistic children are savants. Many Savants are Autistic, but most Autistic people are as normal as Neurotypical people with no particularly special talents.
No, Autistic children are not damaged so they do not need to be healed. Marijuana can help with Autism symptoms such as anxiety, but equally in some Autistic children it can make problems worse.
Feral children may act similar to severally autistic children, but the conditions are different. Autism is caused by genetics, feralism is caused by extreme neglect, so feral children are technically not autistic, though I've seen theories that say only autistic children are capable of figuring out on how to live in the wild, and therefor all feral would be autistic.
Autistic children can do many things that other children whom are not autistic do on a daily basis. I advise showing him/her how to do it safely and be patient with the child. Good luck!
No.
The parents of autistic children really have their work cut out for them.
There is no such thing as a person who can see the future, that is fantasy. Autistic people and savants are not psychics, they are just Autistic and/or savants.
Autism isn't something you 'get' you are born autistic - anyone can be born autistic, although there does seem to be a gentic link so often autistic people are more likely to have autistic children, or you often see multiple siblings in a single family with autism. As yet we don't know what causes autism, so we can't tell who is more likely to have autistic offspring.
Autistic children DO feel pain.