Hi David, thank you for your answer.
I spent some days trying to get a solution by myself, and I fixed all except the excerpt part.
The idea is, as I pointed out before, to change the lenght of the excerpts to cover all the paragraph “square”. A page of example with problems is linked here.
Also, I have another little problem. Should I post it in this topic or open a new one?
Thank you all.
Miguel Á.