all donator commands do work on servers just to clarify unlike with [donator] . [MOD] , [Admin] tags being funny
the !skeleton command when used on sniper can take a few seconds for the server to notice you want to be a skeleton and you should be alive when using the command otherwise again it will fail to make the change i would suggest making a bind for it (bind = "say /skeleton") then u can toggle it when wanted
as for sm_mypitch when used in say dustball classwars it does have a limit of 300 from memory last time i used it