Running 'steam -silent' starts Steam in the system tray without opening the main window, but once it opens, it still doesn't minimize to the system tray.
'STEAM_FRAME_FORCE_CLOSE=1 steam' seems to work for now if you click on the 'X' to minimize it. Thanks.
Nothing extracted yet.
Steam doesn't minimize to system tray when running lxpanel. It stays on the taskbar. I don't know if this is the default behavior on Linux, but on Windows if you minimize or click 'X' Steam minimizes to the system tray.