while working on a case found following useful link and thought of sharing it
http://blogs.technet.com/b/edgeaccessblog/archive/2010/03/25/how-to-publish-citrix-xenapp-5-x-with-uag-2010.aspx
As i mentioned long time back about scenario 2. I posted this blog on ISA/TMG and its link is http://blogs.technet.com/b/isablog/archive/2011/01/13/random-authentication-prompts-while-accessing-internet-through-isa-server-followed-by-isa-server-becoming...