About the issue with to much 'air' between the header and the content, you can try to update ezwebin to a more recent version of ezwebin v1.1: http://zev.ez.no/svn/extensions/ezwebin/stable/1.1/
But it's not 100% fixed before version 1.2, the one that was included in eZp 3.9.2. But to upgrade to 1.2 you need to run a upgradescript because of some changes.
Hello Gregori, the images that are displayed in gallery full view are proportionally resized.
When ezpublish displays images through attribute_view_gui, a needed parameter is the 'image_class' which defines the maximum width and height of the image for a view.
As André comments, try changing in your image.ini the size for gallerythumbnail to something like:
The size of the div is based on the height of gallerythumbnail as defined in image ini, so changing the height as Jacobo suggest from a 200 to 180 height won't help much.
The settings I posted above is from a ezwebin 1.2 installation, and should work a bit better.