Can anyone give me advise on how to arrange and frost cupcakes like it is a sheet cake insead of a bunch of cupcakes? And can you put a frozen buttercream transfer on top of the these cupcakes using this tecnique?

Everything you ever wanted to know about cupcake cakes:

http://www.cakecentral.com/cake-decorating-ftopict-57413-.html

How To Create a Frozen Buttercream Transfer:

http://cakecentral.com/articles/73/how-to-create-a-frozen-buttercream-transfer

HTH