re:1 - No. If the page is primarily content based rather than app based then a fixed width design may well be the best thing for the user; the readability of a design is heavily effected by the interrelationship between factors such as type size, line length, line height etc. Changing the line length without effecting any other aspect of the design can easily have an adverse effect on readability. If your user's primary task is reading, you have just done your users a disservice.

While some fixed width designs are because the designer went nuts with the rasters and making it scale is hard, many designers are doing it for good reason.

[citation needed ;) ]