Did you use browser tools to look at the markup of your site’s main nav anchor tag after clicking on a pagination link?
It is not a browser issue either, because the same thing happens in chrome on your site (this page https://www.nextgen-gallery.com/basic-slideshow-gallery/). Inline style appears in the markup.
The ‘ghosted’ images as you describe is due to lazy load plugin, which I just installed to test. I believe I can filter certain parts of the site from being lazy loaded. Yet another plugin conflict with Nextgen!
You haven’t addressed this issue:
“every image in the gallery is having its containers’ markup output (minus the actual image)”. Again, that would involve looking at the markup, and confirming whether that is a bug or expected behaviour.
I’m being as specific as I can be. Please also do the same so I know how to proceed.