No need to set objects and actions???

Nothing changed. As I tried to detail the differences in this other forum thread , there are "Wall Posts" and "Open Graph Actions". In short:
* Actions can be automatically posted to a user's Timeline without them seeing or editing the post first. They do, however, need approval from Facebook before they will work for all users.
* Feed/Wall Posts should be displayed to the user or allow them to edit and approve the post before it's pushed to their Timeline. Because the user has to explicitly choose to make the post, it does not need to be approved by Facebook.

The code you're using above is for a Feed Post, not for an Open Graph Action post. An Open Graph Action post has a lot more context and Facebook can use that to aggregate things, such as "10 of your friends cooked a recipe". The action is cook and the recipe would be on your site. It's great when you get a lot of Actions posted as they get more users to do the same things.

Feed Posts are just status updates that look like they came from the user.

If you're using the code above, that may be perfectly fine. However, you need to make sure you're following Facebook Application Policies and properly notifying the user of the post and/or letting them see and edit it before it's posted. While I've never seen it happen, violations of their Policies could mean that they revoke your API key.

I hope that helps explain,
Alex