When entering Juicebox-Pro configuration options into the Pro Options text area, be sure to enter each option on a line of its own and enclose the value in double-quotes (as noted in Step #4 here), for example:

enableLooping="TRUE"
stagePadding="20"
galleryTitlePosition="TOP"

Also, please note that Lite Options should be set via their own individual input fields in the plugin's interface (and not in the Pro Options text area).

Please post an example of something that you are entering into the Pro Options text area which is not being saved and I'll investigate further.

I'm glad you're making progress. Thank you for letting me know.

Unfortunately, there is no configuration option available to enable/disable captions. A NextGEN sourced gallery will use the 'alttext' as the image title and the 'description' as the image caption.
However, you can hide the entire caption area by setting captionPosition="NONE" (in the Pro Options text area).
Alternatively, if you want to hide just the image titles or the image captions, then you can do so with a quick edit to the plugin's 'config.php' file.
Just open the 'config.php' file in a plain text editor and:

(1) To hide the image titles, comment out line 95, changing:

$image_element->appendChild($title_element);

... to:

// $image_element->appendChild($title_element);

(2) To hide the image captions, comment out line 102, changing:

$image_element->appendChild($caption_element);

... to:

// $image_element->appendChild($caption_element);

(Please note that the line numbers above refer to the current version of WP-Juicebox, v1.5.1.)

The Splash Page takes the gallery dimensions (the galleryWidth and galleryHeight from the embedding code).
The image used for the Splash Page (by default the first image in the gallery or the splashImageUrl if set) is scaled to fill (rather than fit within) the Splash Page dimensions and, if the aspect ratio of the Splash Page does not match the aspect ratio of the image, then cropping will occur. However, the image should not be stretched. If it is, then it may be due to custom CSS (possibly from your WordPress theme).
At the moment, your gallery sets showSplashPage="NEVER" so I cannot see the Splash Page and investigate the problem.
However, I would check the CSS on your web page to see if there are any rules which are being applied to all images on the page and which the Splash Page image might be inheriting.
I hope this points you in the right direction.