Features module working confusion
You can use Features without additional modules. In fact, the module page is quite clear about it. Quote:

Features also provides faux-exportable functionality for the
following Drupal core and contrib components:
- CCK fields
- CCK fieldgroups
- Content types
- Input filters
- User roles/permissions
- Custom menus and menu links *
- Taxonomy vocabularies *

  * Currently in development.


In other words, these things can be exported using features out-of-the-box. That said, I recommend installing Strongarm right away, because some of the things above are lined to variables that you will want to export as well. For instance, if you export a content type, you probably want to export its comment settings too.