Well, I needed to do a small edit to mystix code because of a 'this.grid has no properties' error and it does what I want it to do now.
Only setting enableHdMenu: false turns off the header button for the context menu completly. I think this is proper even with concern for grouping and other plugins as enableHdMenu: false currently takes care of enableColumnHide: false too. This doesn't require the GridView's headersDisabled config. columnMove and columnResize still work fine.
initComponent : Ext.grid.GridPanel.prototype.initComponent.createSequence(function()
this.colModel.grid = this;
isMenuDisabled : function(col)
return ('undefined' != typeof this.grid) ? !this.grid.enableHdMenu : true || !!this.config[col].menuDisabled;