[Plugin: NextGEN Gallery] Nextgen Thumbnail Column and Spacing problem

It feels like there should be an easy answer for this, but I cannot find it for the life of me! I apologize if these questions have already been answered in another post, but please direct me there if they have.

3 main problems have occurred when inserting an image list into a page/post:

1) The thumbnails do not span the width of the page; they stop about half-way across the page.

2) When selecting more than 3 columns: The thumbnails display one less thumbnail per column than selected in the first row, and then the other thumbnail is displayed alone in the next row- this repeats. In addition, the thumbnails shrink in size. Here is an example with (__) representing thumbnails and 6 images selected for column:
(__) (__) (__) (__) (__)
(__)
(__) (__) (__) (__) (__)
(__)
(__) (__) (__) (__) (__)
(__)

3) I would like to change the space between thumbnails. Is this possible?

Here is an example from the crippled, barely running website:

https://carstenknoche.com/?page_id=37

Please help!

https://www.ads-software.com/extend/plugins/nextgen-gallery/