If you want to run vbGallery you must go through the install and install everything. If there are issues related to the install or specifically a style when installing then the issue is with the style. Remember our product is a vbulletin addon. We support it to work properly with the default released vbulletin code. We can not claim that other hacks mods or custom styles are going to work without some physical interaction on your part or rewriting mods etc.
This is not uncommon all your issues here are centered on this custom style your using. If you know what your problem is with the custom style now then simply install the gallery and redo anything you need to do with the custom style.