It looks like the CSS of your WordPress theme may be conflicting with the CSS of the Juicebox gallery.
If there are any general CSS rules on the web page which apply to all divs or to all images, then they will also apply to all divs or to all images within the Juicebox gallery.
Try temporarily reverting to the default WordPress theme to see if this makes a difference.

You could initially hide the main image by adding the following to the CSS of your main page into which the gallery is embedded:

.jb-dt-main-frame { visibility: hidden; }

... and then, using the API onImageChange(id) method and JavaScript, set the visibility to 'visible' when a thumbnail is clicked.

Make sure that you are entering the data into the correct fields in Photo Mechanic.
When using Photo Mechanic to add IPTC data to your images, JuiceboxBuilder-Pro takes the 'IPTC Caption' from Photo Mechanic's 'Caption' field and the 'IPTC Title' from Photo Mechanic's 'Object Name' field.

Try validating your web page with the W3C Markup Validation Service and fix the errors reported (there are currently 7 errors and 2 warnings on the page).
Although most of the problems seem to be trivial, once your page's code validates against the Doctype Declaration you use, it should be rendered with greater consistency across different browsers.
Please see here for more information about Juicebox and Doctypes.

If you continue to experience difficulties, try temporarily removing your own custom CSS (the 'base.css' and 'gallery.css' files) from your web page to see if this makes a difference.

Also, your gallery has entries such as:

imagePadding: '10px',

Juicebox expects a numeric value for such configuration options so try using:

imagePadding: '10',

... instead.

In order to embed a Juicebox gallery in any web page, you will need to be able to do two things:
(1) Upload your gallery folder to a web server
(2) Insert HTML embedding code into the web page

Please check with Opencart support to see if they allow you to upload files and folders to the web space that they provide.
If they do not, you would need to find an alternate host for your Juicebox-Pro gallery, such as Dropbox.
Please see this forum thread for instructions on how to upload a Juicebox-Pro gallery to Dropbox.

If using Dropbox, you would then need to insert an iframe (documented as Option #2 here) into your Opencart web page.
Again, please check with Opencart support to see if they allow the use of iframes in their web pages.

@pshaw257

No. Juicebox is fully compatible with Chrome (and all other major browsers).

Juicebox can be embedded in an iframe by following the instructions (Option #2) here.

If you continue to experience difficulties, please post the URL to your web page so that I can take a look and help further.

Absolute URLs such as http://www.example.com/images/ will work only when your gallery has been uploaded to a web server.
Until such time, you could use relative URLs in your embedding code (as you did originally) but you would need to make sure that they are relative to the web page containing your gallery's embedding code.
Alternatively, you could try using URLs with a leading slash to denote your root directory, for example:

<!--START JUICEBOX EMBED-->
<script src="/joomla/juicebox_gallery/jbcore/juicebox.js"></script>
<script>
new juicebox({
containerId : "juicebox-container",
baseUrl : "/joomla/juicebox_gallery/",
galleryWidth: "90%",
galleryHeight: "90%",
backgroundColor: "rgba(51,51,51,0)"
});
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

Please see this FAQ which may help:
When I view my gallery, I see a blank area. Why?

In a Joomla environment, it can sometimes be difficult to know where the page containing your gallery's embedding code actually exists on your web server and, therefore, it would be difficult to point to your gallery folder using a relative URL.
Try using absolute URLs instead, for example:

<!--START JUICEBOX EMBED-->
<script src="http://www.example.com/images/jbcore/juicebox.js"></script>
<script>
new juicebox({
containerId : "juicebox-container",
baseUrl : "http://www.example.com/images/",
galleryWidth: "90%",
galleryHeight: "90%",
backgroundColor: "rgba(51,51,51,0)"
});
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

... changing the two instances of 'www.example.com' in the above example to your own web domain name.

If you continue to experience difficulties, please post the URL to your web page so that I can take a look and help further.

This FAQ deals with the 'Config XML file not found' message': When I view my gallery I see the message 'Config XML file not found'. How do I fix this?

However, your gallery works fine in Firefox v16.0.2 on my computer.
In fact, I have been using Firefox to test your gallery before I post each reply and have never seen the 'Config XML file not found' message in your gallery.
Try clearing your browser's cache before reloading the gallery.

The only other reason that the 'Config XML file not found' message might be displayed is if there is a problem with your internet connection or the web server where the gallery is hosted and your browser cannot fetch the 'config.xml' file from the web server within a certain time limit (approximately 10 seconds).

No. Please see this FAQ: Does Juicebox-Pro include the source code?

Please see the following forum thread regarding Facebook integration.
http://juicebox.net/forum/viewtopic.php?id=358

Also, the following SimpleViewer forum post may be of interest. Although the post refers to SimpleViewer rather than Juicebox, the principle is the same.
http://www.simpleviewer.net/forum/viewt … 628#p46628

Please check that your OGG file has been uploaded to the correct location on your web server and that your audioUrlOgg configuration option is set correctly.
Currently, your gallery's XML file uses the following setting:

audioUrlOgg="http://www.lichtwerk.at/alexandra-ewald/selected/hochzeit/hochzeit-mp3.ogg"

... but going directly to that URL in a browser results in an error 404 (file not found).

The default value for the flickrImageCount configuration option is 50 and can be increased to 500. (The 500 limit is imposed by Flickr rather than Juicebox-Pro.)
If you still see only 50 images after increasing the value, try clearing your browser's cache before reloading the gallery.