First issue is that you probably don't want to be able to delete an admin. You also don't want to delete yourself. I would suggest adding an admin? boolean method to test for whether a user is an admin or not so that it doesn't show the delete option for admins. Something like this in your view would work then:
<% if current_user.admin? && !current_user?(user) %>
| <%= link_to "delete", user, method: :delete,
data: { confirm: "You sure?" } %>
<% end %>
Second is the issue when have two of the same element and get an ambiguous match. For testing a lot of times you only want to select one out of the many. You could just select the first one:
first('.item').click_link('Agree')
You can check out this answer for more info: How to click first link in list of items after upgrading to Capybara 2.0?