I am putting my car into an independent shop for 60k service. Should I need anything other than the below ? I have no previous service records for the car, it was purchased off-lease @ 29k miles. Requesting:

-radiator flush and fill
-new spark plugs
-fuel filter
-air filter
-fuel injector's cleaned ? (gas additive ?? )
-set idle
-Cabin filter

I have handled brakes/rotors and all oil changes since 29k. Any advice appreciated. Does anyone know what "transmission service" entails ? Is it just swapping the fluid ? What about timing chain or timing belt ? Thanks.

__________________
1998 C230
1994 Infiniti J30T
1984 BMW 318i
1987 VW Golf GT
1975 Buick LeSabre Conv.