Below is the expressions broken down into 1 column each.
CABIHours: IIf([work hours]![work code]=60,[hours])
CABIOTHours: [CABIHours]-8
TotalCABIRate: IIf([CABIHours]>8,(500+([CABIHours]-8)*93.75),[CABIHours]*62.5)
ProjectManagerHours: IIf([work hours]![work code]=14,[hours])...