If you have a photo printer, you can use a chart like this: http://regex.info/i/FocusChart-v1.0-gray05.gif
The blog entry the chart is from, is here: http://regex.info/blog/2008-12-16/1029
Canon has an option to micro adjust focus but I think it may only work if you use Canon lenses. Nikon may have a similar limitation. Focus is a combination of lens and body so you may have to send a lens or two for repair.
I’m marginally more awake than last time I visited this thread. Looking at the photos now, I notice with most of the edits, I like looking at your mountain more than the couple! That may be a strong argument for using one of the blur tools to change your background, or to concentrate on getting the light right for each part of the photo. As it is, your couple becomes the foreground interest objects in a landscape photo instead of the background being the support for an environmental portrait.