Changing the layout doesn't remove things. ;-) I don't mind
losing the advertisement, or the nodelets when viewing
posts. But I like being notified about followups at some
place, so removing the nodelets everywhere isn't an option
for me (and I don't tend to visit the front page, the only
page for which you can get a different set of nodelets).
As for the CSS, neither the FAQ nor the user settings page
provides a link with useful information (e.g. the structure
of the page), and I don't feel like reverse engineering.