I love doing things from the command line; if nothing else, it lends itself to automation. Here are a few tips and tricks.
No, yes, and sort of - it depends on what you want to do.
No, there is not a command-line logon and session interface for terminal services.
Yes, you can have a remote command line session on a Windows 2000 Terminal Server. Turn on the built-in Telnet service.
The somewhere-in-between alternative is to use the capacity planning tool called smclient. It can be scripted and does an excellent job of screen-scraping glyphs ("glyphs" are various text symbols displayed onscreen, including text in console windows, title bars, and icon names).
Yes; see the Clues on Installing Windows 2000 Terminal Services page.
This can be done through a call to the Terminal Service component install file, without requiring install or uninstall.
To disable Terminal Services:
%SystemRoot%\System32\rundll32.exe setupapi,InstallHinfSection TerminalServices.ToggleOff 128 %SystemRoot%\inf\tsoc.inf
To re-enable Terminal Services:
%SystemRoot%\System32\rundll32.exe setupapi,InstallHinfSection TerminalServices.ToggleOn 128 %SystemRoot%\inf\tsoc.inf
They vary depending on version and configuration; many apply to XP as well. I ahve a summary list of the Terminal Server Console Commands which was pulled from a Windows 2000 Terminal Server in Application mode.