Yes you can
No the Android does not only work with the Verizon phone plan. Yes one can buy an Android phone and use it on AT&T plan.Be aware that Verizon offers an attractive Family Plan with excellent service.
You can use the Kaspersky Internet Security for Android antivirus for your Android tablet.
Cell phone service is not mandatory for an Android Tablet. A Tablet whether Android or Ipad can happily work with Wifi connectivity - if you need to use any internet enabled application.
Definitely yes.
Yes you can use your android tablet for work purposes. You can download apps that will enable you to work using your tablet. New technology is consistently added that will aide you.
Yes, You can now use incredimail on Android tablet by downloading the app in the store. This app will help you check your email and keep you updated.
Generally, No. Although if you purchase the phone unlocked, you can use it with a Verizon prepaid plan.
Yes - go to Android Market
You can search for an .apk of the android market on Google, put it on your SD card, and use a file manager to install it on your tablet.
Yes, it does. But not necessarily from an phone. If you don't have a data plan for your android phone, you can use sites like androlicious to search for applications or games. But to install apps on the phone you will need a WiFi connection or mobile internet.
yes - You do not need the Android Plan from cricket to access and use the Android Market. But you would only be able to access the Android Market via WiFi.