"check/inspect" Items In Maintenance Schedule

[Bob LS430]

I own a 2002 LS430 with 146K miles on it. I keep up with recommended fluid and belt changes and have needed relatively few actual repairs. Lexus recommends periodic checks/inspections of a long list of things as part of the recommended maintance schedule. For example, Inspect differential oil, Inspect drive shaft boots, Inspect fuel tank gasket, etc. I admit I tend to regard this as a way to pad a maintenance bill but am willing to consider otherwise.

How important is it to pay someone to do all of this checking? Has anyone ever had such an inspection actually prevent more costly maintenance? Are some items more important to check than others?