When creating a new entity some of the choices you make will stick with you for the life of the entity. Prior to CRM 2011 the general advice used to be turn on things if you think you might ever need them. For example, Notes and Activities – in the past if you didn’t enable them there was not a supported way to enable them.
CRM 2011 changes this, most of the options like these in the Communication and Collaboration section can be enabled later. The defaults though that come up have them enabled as you can see below:
The + sign next to an item indicates that once enabled it cannot be disabled later. So what I recommend is unchecking all of them and only enabling it WHEN you need it. Ideally in the future maybe the new entity form will get updated to not have those defaulted but until then take a few seconds and be smart about what you need!