Yes, I've seen the denyweapon thing abused before, by immature admins. It's a good idea, just it needs to be used properly, and probably only by the server owner.
What if a command could be made that stuck with a player's GUID in the same way a ban does. Say a player intentionally nades their own base, then they get a 3 day "nade ban" on the server, where they are disallowed from purchasing said weapon. Same with luci-spam, or psaw parties. Also, if the command is for a set period of time (say three days) and not revokable, admins would be less likely to abuse it. (generally abuse occurs for a game or two, then admins tire of it.) And if it sticks around for 3 days, the server owner will be more likely to notice it in the logs if that command is being abused, and can sack the abuser.
