1. It is a great plugin. Why not post a help request in the EnlargeIt! thread?
2a. Graphics/buttons are the user's choice. Joachim Muller even added a selection to config. No changes are planned.
2b. It should be possible to add titles/tooltips to those buttons, maybe something simple in the next maintenance release.
3. Video problems can't be tested by me. Your report of trouble means nothing without a link to your gallery.
4. I will take a look, but am not optimistic. I might be able to reduce the size of the .js. Maybe for the next maintenance release. Maybe.
5. Why not simply choose "Hide Animation" in config.? That will darken the background. Or edit script.js and find this line:
Maybe it will be a config. option in the next maintenance release. At the moment I have been changing the border and background colors, the opacity should not be too difficult to change.
It would not be possible without extensive modifications.
If you want the LightBox to start directly from an album thumb then extensive code modifications would be needed. That is something I do not have the time for now. I will keep it in mind for a future revision.
Please just stop asking. It will not happen anytime soon or at all. If I decide to actually try to crack that problem it will be many months before anything is released.
7. Moving the image up is possible and tested. Maybe I will set something in config. for the next maintenance release.
The estimated time for the next maintenance release is a few weeks to a month or so, maybe longer. As has been written before changes / additions / creations to a cpg 1.5.x plugin are not trivial to make. There are standards of language accessibility and testing requirements that can be quite time-consuming.