Hey Bruno,

I am really sorry for the delay of this reply as it is a weekend for us here. Please find my response to your inquiries below:

1 - Can I delete one Block already inserted? How?

There's 2 ways to do this:

1. Highlight the block and click on the "Remove Block" button on the toolbar, http://screencast.com/t/84rzUF4FKCa7

2. When you click and drag the block, you'll notice that the right pane has a "Trash" section. Just drop it there

2 - Can I reorder Blocks position? How?

Drag and drop the block accordingly

3 - When I insert a Block (youtube video for exemple) it is altomatically inserted into a Text Block, is it normal?

You can actually drop blocks into positions that you want. See my screen shot here, http://screencast.com/t/mINsyFWYAJi

4 - I Inserted a youtube Video and Table, but did not find a way to Align it in center of the article, Is it possible?

Ideally, you should place the youtube block on a new row and choose the "Fluid" layout on the right. This would allow videos to be responsive