1. I picked some option to show a menu when right clicking on the desktop and now I can't undo that. I want to adjust the background image of the desktop actually but I can't find where to do that.

2. The buttons or icons in the task bar representing my windows don't seem to resize if there are a lot--they just disappear off the right side. Can that be adjusted?
3. I think this is a bug in Thunderbird, but in LXDE the fonts in Thunderbird are very small. I mean the fonts for the system menus etc. They are smaller than any other app, but in Gnome they are not--they are normal. I did read on the Ubu forums that in 2007 at least there was a bug like this reported on the Thunderbird app in Ubu's repos and someone said to get Thunderbird from mozilla.com. I just don't want to lose all my settings etc. Any advice here?
Thanks!