I still haven't formed my opinion on Daniel Craig as Bond - he's very different. The film was entertaining though.
As far as the Venetian house - no, they wouldn't have destroyed a patrician house on the Grand Canal. It was done at Pinewood Studios (says IMDB). Also, that's the first time they've let a personal yacht sail on the Grand Canal between the Rialto and Accademia bridges in several hundred years. Fun stuff.