PoS still encourages using more powerful hardware and faster internet because it equates to more transactions. That said, I've seen people use Pi's as stakers. But you can still test the current draw per transaction much the same as with PoW currencies.
More power doesn’t equate to more throughput in PoS schemes, unless everyone is increasing their power and communication isn’t your bottleneck, but even then there’s a quick ceiling you’ll reach.
Not really, you can evaluate PoS-based by the bandwidth and the message complexity of their consensus mechanism and the space required to sync and run a node.