Will s2Member protect content excerpts, feeds, searches, archive views?
Yes. In the s2Member software, we refer to these as Alternative Views.
See: WordPress Dashboard → s2Member → Restriction Options → Alternative View Protection
Searches, Feeds, Comment Feeds, Custom Menus, Page Lists, and More!
s2Member protects Categories, Tags, Posts, Pages, Files, URIs & more. However, even with all of those security restrictions, it's still possible for protected content excerpts to be seen through Custom Menus, XML feeds, in search results generated by WordPress, and/or (depending on your theme), possibly in other Archive views; which might include: Posts by Author, Posts by Date, a list of featured items formulated by your theme, or even through other widgets/plugins adding functionality to your site. ~ We refer to all of these collectively, as "Alternative Views".
With s2Member's Alt. View Restrictions, you can tell s2Member to protect some (or all) of these "Alternative Views", by filtering WordPress database queries for you. s2Member can automatically hide protected content that is not available to the current user. In other words, s2Member is capable of pre-filtering all database queries, so that excerpts of protected content will not be allowed to slip through.