I'm not sure it is useful now, nor what kind of reward that could be worth, but I wanted to let you know nonetheless.
Wallet / node for Pi sounds like a great idea to me.
Keeps network strong at virtually no cost. Would be great if POS added.
I'm up for having pi node online (well at least till provider says ouch)
In fact how's about wallet / node on pi, plus simple p2pool (also on pi), so pi can help maintain network, simple p2pool allows mining rig, to connect and solo mine if required.
Splits POW from POS, best of both worlds maybe?
J