Thanks for the additional tip on the VM registry. I've tried a couple of times to modify the link in the OP (it worked in the preview, but not when posted). However, there is a working link in message number 7 of a discussion of this same issue on the Adobe forums:http://forums.adobe.com/message/3116950
Maybe that will get interested parties to the page, but unfortunately, it doesn't shed any light on how to make the fix on a system using LXDE.
Further research suggests that this may also be connected to use of Openbox as the window manager in LXDE. I've found some instruction on the FAQ page of the Sourceforge pages for LXDE, indicating that LXDE can be modified to use different window managers. I will probably try that, and perhaps the suggestion of modifying the VM's registry entry. Both options are a bit beyond the cusp of my current knowledge, but learning new things is one of life's great pleasures. I suppose just changing to KDE might also allow me to apply the changes for which I've found instructions. But meanwhile, I'm still open for suggestions.UPDATE
: I seem to be making headway, after reading up a bit on Openbox. I've modified ~/.config/openbox/lxde-rc.xml to change some "mousebind" entries. This file is (surprisingly) editable by a normal user, to make more changes in window, keyboard and mouse behaviors than I would have imagined. About half-way through the file, after the section for <keyboard>, is the <mouse> section. In the default install, the first "context" section starts like this:
<mousebind button="A-Left" action="Press">
<mousebind button="A-Left" action="Click">
<mousebind button="A-Left" action="Drag">
After saving the entire file with a .bak filename (I screw up more often than anyone), I changed the "A"s to "W" in these three entries, and saved the file. I'm not sure how many really needed to be changed, but I'll try to figure that out later. After logging out and back in, the window movement is now controlled by the "windows" key, rather than the <Alt> key. That is, holding the "windows" key and left-clicking the mouse anywhere in a window now displays the four-way "move" arrows, and I can move the entire frame of a window with the mouse, as was previously done with <Alt>+click. Unfortunately, I'm doing this on a little computer that has a VM installed, but no version of Photoshop. I'll have to wait until much later to test this on my main machine. But I found the discovery of this too exciting to wait.