I think you slightly misunderstand me here. I definitely can see multisigns being fairly user-transparent and friendly.

256+ "exotic" transaction types ? not so much. But I guess it is best to start discussing the issue when a lot of "exotic" stuff starts popping up.

As long as exotica goes to a separate addresstype and Auntie can keep sending coins the old way, oblivious to the "pro stuff", I am okay.