This line is a little wordy: 
The EJB interfaces, custom exceptions and other transfer objects are split into a separate jar which are packaged in the ear/lib which allows all sub deployments of the ear to see the classes of the ejb-api jar in their classpath.  

 suggest:
The EJB interfaces, custom exceptions, and other transfer objects are split into a separate jar which is packaged in the ear/lib. This allows all sub deployments of the ear to see the classes of the ejb-api jar in their classpath.