It sounds like you have already solved your problem but for any other users reading this post and experiencing similar symptoms (a blank area where the gallery should be), then this FAQ may help.
When I view my gallery, I see a blank area. Why?

Also, it is not possible to isolate a Juicebox gallery (or any other HTML element) from custom CSS on a web page so if you encounter a CSS conflict, please ensure that you do not use global CSS rules but instead apply CSS rules to only those elements on your web page which require them through use of CSS selectors (classes and ids).

First of all, please ensure that you are using the most recent version of Juicebox-Lite (v1.4.2) to ensure that any bugs which were present in previous versions but which have since been fixed are not contributing to your problem.
If necessary, you can download the current version of Juicebox-Lite from the download page here.

If your gallery sets screenMode="AUTO" (the default value for this configuration option), then your gallery should be displayed in Small Screen Mode on small screen devices (like the iPhone). (Please see here for more information on how Juicebox adapts to different devices and screen sizes.)
Do you see the problem in both Chrome and Mobile Safari on your iPhones or just in one of these browsers?
Are you able to upload screenshots somewhere of what you are seeing on iOS 7 vs iOS 8 so that I can see what you are seeing? (For example, I do not know if your gallery uses a Splash Page and whether or not this is displayed.)
Also, it may help if I could see the gallery in question so please post the URL to your gallery's web page so that I can investigate further. Thank you.

The handling of images is done entirely by WordPress itself and WP-Juicebox just displays the images in the order in which they are provided by WordPress (using WordPress's own 'menu_order').

The images should not be in a random order unless you set randomizeImages="TRUE" in your gallery.

If you edit a post containing a gallery, click the 'Add Media' button and go to 'Insert Media (side menu) -> Media Library (tab) -> Uploaded to this post (drop-down menu)', then the images should be displayed in the same order on screen here as they are in the gallery.
If this is not the case, then you should be able to drag and drop the thumbnails into a new order. If you just move a single thumbnail (and move it back to its original position), this should be enough to snap the images into order.

WP-Juicebox (since v1.3.3.1) includes a quick and easy way to reverse the order of images in a gallery (if they seem to be reversed for whatever reason). Just edit the gallery on the 'Manage Galleries' page and select 'Ascending' or 'Descending' as the 'Image Order' before clicking 'Save'.

I hope this helps.

Please see this FAQ:
Can Juicebox handle a custom data source, for example RSS or Instagram?

Essentially, if you do not use a static XML file, you would need to point Juicebox towards a server-side script (using a configUrl entry in the gallery's embedding code) which would dynamically build the gallery's XML file using the images from your custom source.
You can see the structure of a gallery's XML file (that your server-side script would need to replicate) by examining the sample 'config.xml' file from the Juicebox-Lite download zip package ('juicebox_lite_1.4.2/web/config.xml').

There is an example of using a PHP file to display images in a designated folder in this forum post.
It is not what you are looking to achieve but demonstrates that Juicebox is flexible enough to use a custom source of images.
As long as you can fetch the URLs of your images using a server-side language, you should be able to construct an XML file for use within a Juicebox gallery.

I hope this points you in the right direction.

Perhaps any other Sharepoint users reading this can help further and contribute with the code you might need to use.

When you select the 'Add SEO Content' checkbox, code in the following format is added to the Juicebox gallery container (the 'juicebox-container' div).

<!-- Image gallery content for non-javascript devices -->
<noscript>
<h1>GALLERY TITLE</h1>
<p>GALLERY DESCRIPTION</p>
<p><img src="images/IMG_1249.jpg" title="IMAGE #1 TITLE" alt="IMAGE #1 CAPTION" /><br>IMAGE #1 TITLE IMAGE #1 CAPTION</p>
<p><img src="images/IMG_1253.jpg" title="IMAGE #2 TITLE" alt="IMAGE #2 CAPTION" /><br>IMAGE #2 TITLE IMAGE #2 CAPTION</p>
</noscript>

As you can see for the sample code above, both alt and title attributes are included in the img tags.
However, the code is not rendered by the browser and displayed on screen (unless JavaScript is disabled) but is there to help with search engine optimization.
Please see the SEO support section for further details.

I hope this helps to explain this feature and what you are seeing.
If not, then please post back and explain in greater detail what you mean by "alt title not showing and image source show instead" so that I can hopefully help further.

When you create or edit a gallery with JuiceboxBuilder-Pro, the baseUrl is not used and you need to add it to your embedding code manually afterwards.
However, if you are just editing a gallery, then you just need to replace the updated gallery files (in the gallery folder) and there is no need to alter the embedding code at all.

The Lightroom plugin v1.2 came bundled with Juicebox v1.2.0 so, if you upgraded the plugin to Juicebox-Pro around that time period, then the version of Juicebox that your gallery is using is almost certainly the cause of your problem.
You can determine the version of Juicebox that a gallery uses by opening the gallery's 'jbcore/juicebox.js' file in a plain text editor and checking the version number in the comments at the top.
You can do likewise with the plugin's 'juicebox.js' file ('juicebox.lrwebengine/jbcore/juicebox.js') to determine what version the plugin is currently using.

As you will likely need to upgrade the plugin's core Juicebox files, you might like to take this opportunity to upgrade the plugin, too.
(1) Download the latest version of the plugin (v1.4.2.0) from here.
(2) Download the latest version of Juicebox-Pro (v1.4.2) using the link from your purchase email (see here for details).
(3) Upgrade the Lightroom plugin following the 'Upgrading to Juicebox-Pro' instructions on the plugin's support page.

If you want to upgrade an existing gallery to the latest version of Juicebox-Pro, then either recreate the gallery with the upgraded version of the Lightroom plugin or replace the 'jbcore' folder in the existing gallery folder with the 'jbcore' folder from the Juicebox-Pro v1.4.2 download zip package ('juicebox_pro_1.4.2/web/jbcore/').

I would recommend following the baseUrl method of embedding as documented here.
Essentially, you would upload the complete gallery folder (not just the contents) to your web server and enter the baseUrl embedding code into your web page wherever you would like the gallery to appear. It does not matter where on your web server you upload your gallery folder to as long as the two paths within the embedding code (the path to the 'juicebox.js' file and the baseUrl itself, pointing towards the gallery folder) are correct.

Keeping the gallery files within the gallery folder should help keep things organized on your web server and also makes life easier if you want to update the gallery in the future (as you would just have to replace the complete gallery folder on your web server).

Please ensure that you enter the baseUrl embedding code into your web page as HTML code rather than just plain text.
Chapter 7 in this web page may help with this.

Do you have a link to a gallery which still displays the flickering so that we can take another look (now knowing what we know about the server-side caching issue)?
The link in your earlier post does not seem to work any more.

Also, do you see the problem (in your Safari browser) in this demo gallery which uses imageTransitionType="CROSS_FADE" and displays navigation buttons?

Thanks for your help.

In the next version of Juicebox, thumbnails within a gallery will still all be the same size as each other (they do not need to be square) but the images used to fill the thumbnail dimensions will be scaled-to-fill. This is certainly an improvement over the current behavior (which center-crops images) and allows for images which are nowhere near the thumbWidth and thumbHeight dimensions to be used as thumbnails, although it is not what you are looking for.

Please feel free to post suggestions for future versions in the Feature Requests thread. This keeps all the ideas together and ensures that they are not overlooked by the developers.
Thank you.

On further investigation, the problem may be related to server-side caching.
If caching is disabled on your web server, then Juicebox will have to download the images every time it needs them (as it will not be able to request them from a cache) and this may be causing the problem.

If you have an Apache web server and have a .htaccess file with an entry such as the following (to disable caching), then please try removing it to see if it helps.

Header set Cache-Control "max-age=0, private, no-cache, no-store, must-revalidate"

This may solve the problem.