(Sorry for the wait)
You can weigh the chained platforms by throwing the deactivated Armos onto one end. The more Armos on the platform, the heavier it will be. It's a scale platform.
There's a bombable wall next to the left platform that leads to somewhere.
And then I *think* there are arrow-eye platforms in the next room?
Yes, he's done that I think. (I'm playing SPM right now, but this would be good to know later) Say he's in the room with the lightning gate, how does he get through?