> I was wondering if there's a way to dock the Histogram window?
There are two histograms in the viewer - the separate one from Image | Histogram and the one in the Viewbar. The latter is supposed to be dockable but (at least for me) it isn't.
> I find the hover preview just fine for the thumbnail images. What I think would be nice is when a thumbnail is selected the docked histogram windows would be updated.
The hover preview, of popup tip as it's called, shows the thumbnail, not a histogram, so I'm not sure if I'm understanding you correctly. If you'd like to have a histogram panel in the main program (i.e. with the thumbnail listing, not the viewer) then that's something that you could definitely suggest to Cerious by e-mail (this being a user-to-user forum, where the Cerians don't visit often).