I can't say I've ever used my PMs irresponsibly, unless you mean things like 'Where have you been? What are you up to?) sort of things, which often appear on the forums anyway. I do know somebody who has done, but he's one of those who were banned in that incident.
As for LHs suggestions, they all seem perfectly sensible, and very straightforward. I too would be in full support of a mod reading through my Pms if it meant we could keep them.
I would just like to ask whether the large amount of PMs being sent back and forth between members (mods not included, and ignoring any 'irresponsibility;) is actuall any trouble, or whether it is more or less automatic.
To be honest, I haven't seen any probles once LHs suggestions are put into effect.