Is it possible to "fake logoff" a VNC session, so that when I log off programs continue to run? For example, I log onto my remote computer, start Firefox and open a couple of tabs and download some large files and then "logoff," and when I re-logon, Firefox is still open and the files as still downloading?
VNC session is not the same as logon session. Sure you can connect and disconnect through VNC not affecting running applications. You can start Firefox or anything you want, then lock the screen for example and then disconnect VNC. When you connect through VNC again you will see the lock screen again. All running apps would work.