Some of these options, such as disabling automatic updates, would reduce security. But some, such as DNS prefetching, impact only performance and disabling them

Some of these options, such as disabling automatic updates, would reduce security. But some, such as DNS prefetching, impact only performance and disabling them would improve security (confidentiality is a key part of security), however marginally in some cases. I think a distinction needs to be made for the users.