To test if system is working you don't need any of these. Only thing I'm not sure of is the VLSI chip. But maybe the headless theorie is correct.

If the system boots the floppy drive will react.Same as the harddrive. You won't see anything on your screen but it will react....

So I would clean up the motherboard and parts and test. I ounce cleaned a PowerBook motherboard in a dish washer. No problems with it after drying.