This approach of Cade's book is already been criticized in this forum:
https://coderanch.com/how-to/java/CadeSheilSceaFaq
Moreover there are few approaches for class diagrams:
1) Be very high level-just provide BDM and entities
2) Provide as in point 1 plus services
3) Provide point 1 plus point 2 plus DAOs and other important classes
It depends upon you how you want to represent your architecture. I followed point # 3 and all my peers simply termed my assignment too detailed.
Regarding sequence diagram-i didn't provided the internal calls of the framework but everything else. That was also termed low level by my peers.
IMHO i will show all the public methods in the class diagram that i have shown/talked about else where(sequence diagram) in the assignment. If i am using any design pattern-that also i will show on the class diagram. There is no harm to be detailed-it requires extra efforts but i am sure you won't fail it. Moreover with the amount of details-if you are not doing everything in a fast track manner(like me - who can only devote 30 to 45 minutes per day)-it is easier to resume in the incomplete assignment.
Hope it helps.