Solved in SVN 1083 (as long as Debug System is off, that will be solved with the GoogleMaps plugin version 2.17): 1. Problem with My Galleries: tabs show up above each other (as in your screenshot.jpg)
=> It's a combination of the tabs/panes used combined with the use of "googleMaps plugin". Right now I seem unable to solve this/find the exact problem, but I've put out a question... I've tested it with only the code to create tabs from one of these links (without My Galleries showing on the page), and the example code works only without the googleMaps plugin.
http://docs.joomla.org/How_to_use_the_JHtmlTabs_in_a_component
http://docs.joomla.org/How_to_use_the_JPane_classes_in_a_component
http://extensions.joomla.org/extensions/maps-a-weather/maps-a-locations/maps/8213

Currently the only 'solution' I can think of is a workaround: set the googleMaps plugin up in such a way that it doesn't show in the pages where the user might use RSGallery2's My Galleries, which is the RSGallery2 menu item (for the root gallery).

2. Default state for upload images (Setting in Configuration > Images > Image Upload)
Thought it over and will change this such that this setting will apply for users with either Edit State Own or Edit State. Seems the most logical to me since then a use can change the state anyway.

4 Slideshow Parth "keeps loading" -> black screen with bar
- "All slideshows fail": if for each gallery the Slideshow Parth won't load it's not likely that one of the images is the problem on which Slideshow Parth is choking.
- "JoomGallery" doesn't work either on your website.
- Info: The slideshow that is used for Slideshow Parth is JonDesign's SmoothGallery (http://smoothgallery.jondesign.net/).

I'm wondering, since there is a problem with the panes in My Galleries: when you disable the GoogleMaps plugin on the page where Slideshow Parth is showing, does the slideshow work then?

Added this one to the list:
Solved in SVN 1084: 3.3 The image count of the subgalleries (that show at the bottom of a box with the gallery, e.g. "subgallery 1 (2), subgallery 2 (4)" should also have the choice to include the number of items in their childgalleries.

7. Recreating original image in Consolidate Database does not work
=> Let's do this one better: make option "copy display image to originals folder" when "Keep original image" is set to yes (with info), and don't show the entry whent the setting is set to no.

11. Pagination shows as list items and not "on one row"
RSGallery2 uses the pagination class that is available in the template. For Joomla's default template Beez_20 this is:
#main .pagination ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    text-align: left;
}
#main .pagination li {
    border: 0 solid #EEEEEE;
    display: inline;
    margin: 0 2px;
    padding: 2px 5px;
    text-align: left;
}
.pagenav {
    clear: both;
    padding: 2px;
}
#main .pagination li.pagination-start, #main .pagination li.pagination-next, #main .pagination li.pagination-

end, #main .pagination li.pagination-prev {
    border: 0 none;
}
#main .pagination li.pagination-start, #main .pagination li.pagination-start span {
    padding: 0;
}
See also http://www.rsgallery2.nl/display_and_templates/problem_pagination_16730.msg43510.html#msg43510 (and especially http://joomla-css.nl/index.php/en/content-a-component-styles-en-16/pagination-general-en-16).

11. Give the site admin the option to show the pagination only above/only below/above and below an image.
=> Added to the feature request list, but no promises if/when this might get done.

12. JCE editor window width in My Galleries
This is something you need to address with the JCE Editor itself.

The JCE editor cannot be made smaller than the width of its icon set (e.g. the block with the bold, italic, etc. buttons). What you can do is set up a profile (Backend > Components > JCE Administration > Profiles) to use. In such a profile you can set up the area (Front-End, Back-end or both), the Components this profile is uses for (All Components or Select from a list), etc. Then in its Features you can change the Current Editor Layout (remove buttons, add new button "lines" just to rearrange the buttons so that the block with buttons is not so wide, personally, I don't want my users to be able to use all these buttons in the Front-End anyway).

And then in the Editor Parameters you can set the Editor Width, e.g. to 380px (or whatever suits you best).

This is the way to set up your JCE Editor, that you chose to use as editor as opposed to for example the default editor TinyMCE, to suit the needs of your frontend users. (See screenshot CustomJCE.jpg (which also shows the test bar with the panels that won't work with googleMaps enabled on that page.)

Issues resolving so time to customize. I retained upper navigation bar so the 'Next' & 'Prev' buttons stay in one place as images change for a click when ready sort of slideshow. I removed the lower bar and download button to bring the Description up closer to image. I want all images to have a description and for both, being equally important, to be easily seen. I removed the banner so image is seen without having to scroll down as pages refresh. A notch or two turning the mouse wheel and the description can be read. Good enough. Screen shots below.

Tried all editors I could find, wasted a lot of time, back to using JCE which, following your lead, now works fine.

Thanks again, I made a custom copy of the Semantic template. Have made slight changes to display.class.php, gallery.php, and inline.php. It's fun to make little changes. I found 'Size: 15 images' to be a bit much, so now it is '15 images'. Also above the random images it said 'Results 1-7 of 7' which made no sense to me so it went away. In your post on modifying RSGallery2 linked to you mention get J!Dump. Sounds good. Funny it says it is for 1.5, but are you confirming that it works with 2.5?

Good to see you back post-attack on this site. A few months ago all my sites were deleted by Islamist hackers who left only their calling card. Had to upload almost 8gb and remove forum software which I suspect was their way in.

My current project using RSGallery2 (SVN 1082) had to be rebuilt from a clean J! install. Had to install and rebuild galleries. All is approaching perfection. A slight issue was that in reentering about 30 galleries/subgalleries, I had to work from the bottom of list as each added gallery appears on top rather than added next to bottom. Images are added to bottom. Would be preferred if galleries were added to the bottom of the list.

Another issue involved JCE which for some reason defaults to excluding super users from using JCE on front-end. So until I fixed that, when I tried adding images through front-end logged on as admin, a Description box came up without icons instead of JCE. I could type into the box, but CTRL-V is disabled so in reentering all the photos I couldn't paste in descriptions and had to use the back-end where JCE came up.  So whatever box came up from wherever, it should at least allow CTRL-V. This is not a serious problem, but is a curiosity to mention.

Otherwise, I might mention that for member permissions I ended up having to use settings the following attachment shows to get everything working the way I wanted. Others may want to note.