1. Is Android running on top of Java? may be silly but still.
No. It has Java syntax and the code is executed by Dalvik runtime, which is a register based custom virtual machine. Pay a visit to AndroidFAQs(link in my signature).
2. If not, is it platform neutral? How exactly it fits the bill?
Android is not just a language. It is a complete software stack. Read What is Android?
3. Are there any significant changes one has to adopt while switching from normal Java EE web apps to Android? What would you suggest?
6. Pro Android Web apps -- basically Android is for Mobile Apps. Right? Is nt it contradicting? I may be wrong on my understanding.
As per the Android FAQ,it still says, "Android is a software stack for mobile devices that includes an operating system, middleware and key applications". How is the "Android Web Apps" then? I am slightly confused. What is the term 'web Apps' has to do here?