Hiya, Linux on PS3 is good, but "unfortunatly" for the running of certain applications, it's based on PPC. Which means you can't use Adobe Flash for Linux. Because these applications are made for x86 & x86_64.
Too run flash on PS3, you'll have to use a flash application build for PPC.
As for your second question, can't answer that one, not into shoutcasts, but i do know that amarok supports radio streams.