offsetting center of maps

You will need to remove all the references similar to this:
marker_3.openInfoWindowHtml(address_3.infowindowte xt);

Unless they are surrounded by the addListener function:
GEvent.addListener(marker_3, 'click', function() {
marker_3.openInfoWindowHtml(address_3.infowindowte xt);
});

The ones not in the addListener functions are run when the map is loading(as each marker is loaded). The ones in the addListener functions are triggered when you click on the marker icon.

In addition, you will want to remove all other setCenter function calls so they don't interfere with the centering you are applying.

The marker info will not show up after the map has loaded, but this allows for the center of the map to be able to be set by map.setCenter.