I remember somewhere in one of the Use-Case it says that it will refer to the Price Itinerary Use-Case, but it does at what condition.
No, I did not use timer service. (I dont know why you want to have it in the first place)
For Cade's book, I followed quite closely except the technology portion,
which I feel strongly that the Class Diagram should not contain technology related stuff (as explain earlier in this post).
The notes in Cade's is concise so it let me focus on the real problem.
Another source of the notes I would recommend is to read some of the notes
posted in the this scea_j2ee yahoo group, under the file section there is an enormous amount of material http://groups.yahoo.com/group/scea_j2ee/files/
Lastly one more piece of advise.
As we are training to become Architects, we should be learning the correct basics of the fundamentals of Software Architects, but always keep in mind what makes one Architect differ from the next Architect is STYLE,
or the way you vary your design within the given boundary.
Just think analogous of the building Architect, they are all constraint by gravity, by material available, by current technlogy, but some buildings are "better" built than others.