The fluid meter is a no-go, it requires sensors for all of the fluids and a separate harness for them.
The passenger seat is easier. Your seat can attach to the power-seat frame, but the panel with the switches will be blue (not a problem if you don't care.) The wiring for it is already there.
The switch next to the headlights is for the Autolamp gadget that turns your headlights on/off automatically, there's actually a thread about adding it. A quick search should help you out.
1994 Super Coupe ('93 5.0L swap), 1990 Tbird 3.8L, 1982 Honda CB900F, 1972 F-100 SportCustom 4x4, 1970 Chevy Custom Camper / 20