I don't think deleting inactive pawn accounts would help much at all. It's bandwidth (information transfer capacity) that's the problem, not a few kilobytes of information stored on Fencer's server. If an inactive player is inactive, that's not affecting the site's daily traffic at all.

Also, if we send email reminders in an attempt to bring inactive pawns back, then we're just adding to the traffic, not alleviating it.

The solution needs to generate money for more powerful servers and more bandwidth, without deleting accounts or limiting moves. I'd rather have emails go out to the most active pawns, rather than to the least active. With appropriate incentives, they (at least some of them) might be encouraged to join the site.