Hey Mizz (or do you prefer Raven?),
I have aspergers and my son has autism. The best book on aspergers I have ever read (and I read a lot) is "All Cats Have Aspergers syndrome". It is a childrens book and mostly pictures but it's the best and just a few minutes to read.
The things you are saying about food are sensory issues. Sensory issues are common with aspergers. It just means that our different senses don't filter things the way yours do.
If you are a reader the two publishing houses that publish the majority of good stuff on aspergers and autism are:
http://www.asperger.net/
http://www.jkp.com/catalogue/aspergerautism

My thoughts on autism are not always consistant with mainstream beliefs. I adopted my son because he was in an institution and they thought he would never be able to live outside an institution. He has lived with me for 4 years now and is well on his way towards independent living for an 11 year old. He is in public schools and is mostly mainstreamed. He is also off all meds.

As far as the 7yr old bullying his brother make a strict family rule about treating others with respect. Emphasize the importance of these rules often. Keep them short and simple and in a posted where everyone can see them. Just be careful on wording... He will hold you and his parents to these rules unless they are clearly exempt in how the rule is written. How you say things can be very important as we process language very literally. Make it clear that when one of the rules is broken you/and or the parents are resposible for consiquences. Also, our brains have a very hard time with contractions and "no". It is like our brain doesn't even hear the negation. So... try to word things in a positive way. "we keep our hands to ourselves" is a little long but it will work better than "no pushing". I try to keep rules to 3 or 4 words total but you may be able to be a little more flexible.
A lot of times when we seem to be "misbehaving" it is because we don't understand. Either we don't get that the behavior is wrong or we don't know an appropriate way to get our needs met. Teaching us to do it right will go much farther than any punishment.
If you talk about the video games as "his wii and his DS" it tells him that as "his" he gets to make the decision of who uses them, how and when. A feeling of ownership will often create a strong feeling of responsibility and controling behaviors.

Language is both the hardest and easiest way to help manage autism spectrum disorders. The way you phrase things is deeply ingrained and hard to change. It will, in my eperience, create the greatest changes.

Please feel free to PM me with any questions. If you are having trouble with a specific behavior I may be able to give you a better idea of how he is understanding things. Be as specific as possible and try to include what happened just before and just after the behavior. In school this is called a FBA or functional behavioral analysis.

Keeping a log or journal will also help you discover patterns.