The problem is that the account of concern is grayed.
So what I see now is that I can choose Guest or User but I don't have the Login Items tab. Any idea why?
1. Boot the laptop. Let all those stupid programs open.
2. Wait until everything's opened. Now right-click (or control-click) on the program's icon in the dock.
3. One of the options (under "Options") will be "Open at Login" and have a checkmark next to it. Select it again and the check mark will be gone.
4. Repeat for each of the unwanted programs.
That's it! They won't reload automatically the next time you restart, but are still on the machine and can be invoked normally as needed.