Can Save Terminal-emulator Window Positions and Tabs?

I don't think so, at least not easily.

You can have any app startup automatically, that's doable, so you could have a terminal or two open automatically easily enough.

For window positions, you can tell moksha to remember the position of one window, but not multiple windows of the same app.

And to open shell in previous directory, I imagine that is possible with some kinda bash scripting, saving your directory history, but as far as I know there isn't any command to implement that automatically.