First, there are circumstances around the exam that examinees aren't allowed to talk about. So I can't answer all of your questions. But you do get access to what you need to accomplish what is asked of you. Just remember, there is often more than one way to do things.
However, I can say that the Red Hat virtualization product is KVM, the Kernel-based Virtual Machine. Several RHCSA objectives relate to virtualization. Therefore, you should be prepared to know KVM inside-out. (In other words, VMWare and Virtualbox are essentially irrelevant to the RHCSA.) Be warned, KVM on RHEL 6 requires that you have 64-bit hardware. (Red Hat doesn't even include key KVM components in its 32-bit release.)
Randy Russell, Red Hat's Director of Certification, has stated in a public blog that the exam is delivered "electronically".
As for the exam timing, it was a 6 hour / 3 part exam about 8 years ago -- when there was only an RHCE exam. Today, the RHCSA exam has a 2.5 hour limit. There are some conflicts online on the topic; when Red Hat originally announced the RHCSA, it stated (IIRC) that it would be only 2 hours.
I've posted several "tips" as topics in this subforum. I hope that they can help you. In the interest of full disclosure, I am a RHCSA/RHCE author, ref http://www.amazon.com/dp/0071765654/
, and have been authorized to post as such in this forum. If you want to practice with KVM, I've described how to set up a network of systems in my book using the Red Hat virtual machine solution. For more information on appropriate hardware, see http://www.linuxquestions.org/questi...-exams-899466/