It is not possible to change the name of the thumbnail folder. It is set by Picasa itself and is not user-changeable within a plugin.
However, this should not affect the ability to open and edit the gallery in JuiceboxBuilder-Pro (though any new images added to the gallery will have their thumbnails placed in a new folder named 'thumbs').
If you have any specific issues, please let me know so that I can investigate further.

You can edit the 'header.xml' file to add configuration options just as you did with the SimpleViewer plugin for Picasa.
The configuration options for the 'config.xml' file are taken solely from the 'header.xml' plugin file so any and all options you place in here will be copied across into the output gallery folder.
Make sure you do not have a duplicate or older version of the the Juicebox plugin for Picasa and that you are modifying the 'header.xml' file in the correct folder.

I believe this incompatibility will be fixed in the next version on Contact Form 7.
Try downloading and using the current development version of Contact Form 7 from the 'Development Version' link at the top of the 'Other Versions' list on this page.

If using WP-Juicebox to create your galleries within WordPress, then Pro Configuration Options should be entered into 'Pro Options' text area in the form:

screenMode="LARGE"

Each entry should be on a separate line, e.g.:

screenMode="LARGE"
enableAutoPlay="TRUE"

This is documented in the 'Upgrading to Juicebox-Pro' section at the bottom of the Juicebox - WordPress Plugin page.

This web page may be of use.
It looks like you would need to sign up to followgram to create your Instagram vanity url and you could then use the script to read the RSS feed and fetch the relevant information (image URLs).
You would then need to format the information (stored in the array created by the getFollowgram() method) into the correct syntax required by Juicebox (replacing the HTML code at the bottom of the script).

On further investigation, the problem is caused by your use of jQuery Mobile.
You will need to add the attribute rel="external" to the link to your 'Weddings.html' page on your 'portfolio.html' page, i.e.:

<li><a href="Weddings.html" rel="external">Weddings</a></li> 

Please see the Link formats documentation for jQuery Mobile for more information.

If you wish to use the URL of the actual image itself rather than the URL of the gallery displaying the image, then you can get it using the getImageInfo() method of the Juicebox-Pro API and pass that along to the Facebook Like button instead.

I have not yet been able to implement the Facebook Like button into the caption area but I have been able to display a like button for individual images (whose URL changes each time a new image is selected within the gallery) rather than just for the entire gallery. Please see this post for details.

Try validating the code on your web page with the W3C Markup Validation Service and fix the errors reported.
Once the code validates OK, your web page function correctly.

Your page loads the 'juicebox.js' file twice. Only one instance is required.

Try removing the <p> and </p> tags from around the embedding code. <p> </p> tags should not contain block-level elements such as the gallery's <div> container.

Also, try using folder names that do not contain spaces. As each folder forms part of a URL when it is uploaded to a web server, it would be wise to use only web-safe characters for files and folders.
Please see section 2.3 of this document for details.

You can do the same as you currently do with SimpleViewer by using Juicebox's configUrl option to point to a specific XML file.
A description of the configUrl option can be found here.
The embedding code for your first gallery might look something like this:

<!--START JUICEBOX EMBED-->
<script src="./resources/jbcore/js/juicebox.js"></script>
<script>
new juicebox({
containerId : 'juicebox-container',
galleryWidth: '900',
galleryHeight: '900',
backgroundColor: '#222222',
configUrl : 'galleries/1-HAR2-12.xml'
});
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

Setting enableTouchZoom="TRUE" will allow users to touch zoom within the bounds set by the values in the viewport <meta> tag.
If you set 'initial-scale=1' and 'maximum-scale=1', then the gallery will initially be displayed at the maximum zoom scale.
The user could zoom out but not in. You could, however, set 'initial-scale=1' and 'maximum-scale=2' to allow the user to zoom in beyond the default scale value.
For more information on the viewport <meta> tag, please see this web page.

Thank you for the screenshots. I now see what you mean.
Try adding the following code to the <head> section of your web page:

<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">

If embedding the gallery in an existing web page alongside other content, then the gallery's own 'index.html' file is not required.
This can simply be used to display the gallery on its own page if you like.

Please see the note for Dreamweaver users here.

As you have discovered, you also need to upload your gallery files to your web server.

Try the following. In this example, the gallery folder will be called 'my_gallery'.
(1) Upload your entire gallery folder (not just the contents) to your webserver via FTP.
It does not matter where on your web server you upload it to as long as you know where it is.
(2) Paste the following code into your page in Dreamweaver.

<!--START JUICEBOX EMBED-->
<script src="http://www.example.com/my_gallery/jbcore/juicebox.js"></script>
<script>
new juicebox({
containerId : 'juicebox-container',
baseUrl : 'http://www.example.com/my_gallery/'
});
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

... changing the two URLs in the code above depending on the location of your gallery folder.
This baseUrl method of embedding (which allows you to upload complete gallery folders in their entirety) is documented here.