Pavroo: Thanks, but:
1.) My own strong personal preference is for auto-hide, and the reason is not to hide the dock but to find it quickly. The screen on this laptop is only 26.5 cm by 16 cm, and with auto-hide I could quickly find the dock even when the screen was crowded with several (or a full browser) windows, and not take up precious screen real estate.
2.) I used Wbar-config to try to change the icons on the dock, but none of the Hicolor ones, for example, would show up on the dock even though the software accepted them, and even though they are scalable *.svg files. As soon as I click on "reload", the icon disappears from the dock.
If you have no other suggestion, I'll pursue the auto-hide issue with the LXDE forum. But do you have any suggestions for the icon issue?
Thanks for all your time and excellent support.